261664012 has 6 divisors (see below), whose sum is σ = 457912028. Its totient is φ = 130832004.

The previous prime is 261664003. The next prime is 261664019. The reversal of 261664012 is 210466162.

261664012 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×261664012² = 136936110351872288, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261664019) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32707998 + ... + 32708005.

Almost surely, 2^261664012 is an apocalyptic number.

It is an amenable number.

261664012 is a deficient number, since it is larger than the sum of its proper divisors (196248016).

261664012 is a wasteful number, since it uses less digits than its factorization.

261664012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65416007 (or 65416005 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 261664012 is about 16176.0320227181. The cubic root of 261664012 is about 639.6091461162.

The spelling of 261664012 in words is "two hundred sixty-one million, six hundred sixty-four thousand, twelve".