661072332128 has 24 divisors (see below), whose sum is σ = 1401600474288. Its totient is φ = 305110306944.

The previous prime is 661072332113. The next prime is 661072332161. The reversal of 661072332128 is 821233270166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 794557676 + ... + 794558507.

It is an arithmetic number, because the mean of its divisors is an integer number (58400019762).

Almost surely, 2^661072332128 is an apocalyptic number.

It is an amenable number.

661072332128 is an abundant number, since it is smaller than the sum of its proper divisors (740528142160).

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

661072332128 is a wasteful number, since it uses less digits than its factorization.

661072332128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1589116206 (or 1589116198 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 41.

The spelling of 661072332128 in words is "six hundred sixty-one billion, seventy-two million, three hundred thirty-two thousand, one hundred twenty-eight".