6661511256 has 32 divisors (see below), whose sum is σ = 16759862640. Its totient is φ = 2206359168.

The previous prime is 6661511239. The next prime is 6661511279. The reversal of 6661511256 is 6521151666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 880191 + ... + 887726.

Almost surely, 2^6661511256 is an apocalyptic number.

It is an amenable number.

6661511256 is an abundant number, since it is smaller than the sum of its proper divisors (10098351384).

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

6661511256 is a wasteful number, since it uses less digits than its factorization.

6661511256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1768083 (or 1768079 counting only the distinct ones).

The product of its digits is 64800, while the sum is 39.

The square root of 6661511256 is about 81618.0816731195. The cubic root of 6661511256 is about 1881.5867899347.

The spelling of 6661511256 in words is "six billion, six hundred sixty-one million, five hundred eleven thousand, two hundred fifty-six".