661161256 has 32 divisors (see below), whose sum is σ = 1465632000. Its totient is φ = 273583296.

The previous prime is 661161253. The next prime is 661161271. The reversal of 661161256 is 652161166.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (661161253) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 201936 + ... + 205183.

It is an arithmetic number, because the mean of its divisors is an integer number (45801000).

Almost surely, 2^661161256 is an apocalyptic number.

It is an amenable number.

661161256 is an abundant number, since it is smaller than the sum of its proper divisors (804470744).

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

661161256 is a wasteful number, since it uses less digits than its factorization.

661161256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407161 (or 407157 counting only the distinct ones).

The product of its digits is 12960, while the sum is 34.

The square root of 661161256 is about 25713.0561388568. The cubic root of 661161256 is about 871.1691051377.

The spelling of 661161256 in words is "six hundred sixty-one million, one hundred sixty-one thousand, two hundred fifty-six".