661002012 has 48 divisors (see below), whose sum is σ = 1869504000. Its totient is φ = 200303280.

The previous prime is 661001987. The next prime is 661002019. The reversal of 661002012 is 210200166.

It is a happy number.

661002012 is a `hidden beast` number, since 661 + 0 + 0 + 2 + 0 + 1 + 2 = 666.

661002012 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661002019) 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, 277012 + ... + 279387.

It is an arithmetic number, because the mean of its divisors is an integer number (38948000).

Almost surely, 2^661002012 is an apocalyptic number.

It is an amenable number.

661002012 is an abundant number, since it is smaller than the sum of its proper divisors (1208501988).

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

661002012 is a wasteful number, since it uses less digits than its factorization.

661002012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 556423 (or 556415 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 661002012 is about 25709.9593932001. The cubic root of 661002012 is about 871.0991577076.

Adding to 661002012 its reverse (210200166), we get a palindrome (871202178).

The spelling of 661002012 in words is "six hundred sixty-one million, two thousand, twelve".