51611556 has 12 divisors (see below), whose sum is σ = 120426992. Its totient is φ = 17203848.

The previous prime is 51611537. The next prime is 51611591. The reversal of 51611556 is 65511615.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×51611556² = 5327505425482272, which contains 22 as substring.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

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, 2150470 + ... + 2150493.

Almost surely, 2^51611556 is an apocalyptic number.

It is an amenable number.

51611556 is an abundant number, since it is smaller than the sum of its proper divisors (68815436).

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

51611556 is a wasteful number, since it uses less digits than its factorization.

51611556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4300970 (or 4300968 counting only the distinct ones).

The product of its digits is 4500, while the sum is 30.

The square root of 51611556 is about 7184.1183175112. The cubic root of 51611556 is about 372.3193869389.

The spelling of 51611556 in words is "fifty-one million, six hundred eleven thousand, five hundred fifty-six".