661213046712 has 64 divisors (see below), whose sum is σ = 1689062284800. Its totient is φ = 215605164800.

The previous prime is 661213046707. The next prime is 661213046713. The reversal of 661213046712 is 217640312166.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661213046713) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2084212 + ... + 2380412.

It is an arithmetic number, because the mean of its divisors is an integer number (26391598200).

Almost surely, 2^661213046712 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661213046712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (844531142400).

661213046712 is an abundant number, since it is smaller than the sum of its proper divisors (1027849238088).

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

661213046712 is a wasteful number, since it uses less digits than its factorization.

661213046712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298236 (or 298232 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 39.

Adding to 661213046712 its reverse (217640312166), we get a palindrome (878853358878).

The spelling of 661213046712 in words is "six hundred sixty-one billion, two hundred thirteen million, forty-six thousand, seven hundred twelve".