661203056412 has 144 divisors (see below), whose sum is σ = 1876151676672. Its totient is φ = 195319019520.

The previous prime is 661203056407. The next prime is 661203056417. The reversal of 661203056412 is 214650302166.

661203056412 is a `hidden beast` number, since 6 + 6 + 1 + 2 + 0 + 3 + 0 + 5 + 641 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (661203056407) and next prime (661203056417).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661203056417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 230998 + ... + 1172930.

It is an arithmetic number, because the mean of its divisors is an integer number (13028831088).

Almost surely, 2^661203056412 is an apocalyptic number.

661203056412 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661203056412, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (938075838336).

661203056412 is an abundant number, since it is smaller than the sum of its proper divisors (1214948620260).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661203056412 is a wasteful number, since it uses less digits than its factorization.

661203056412 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942028 (or 942023 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

Adding to 661203056412 its reverse (214650302166), we get a palindrome (875853358578).

The spelling of 661203056412 in words is "six hundred sixty-one billion, two hundred three million, fifty-six thousand, four hundred twelve".