51566646 has 32 divisors (see below), whose sum is σ = 109549440. Its totient is φ = 16136064.

The previous prime is 51566639. The next prime is 51566653. The reversal of 51566646 is 64666515.

It is an interprime number because it is at equal distance from previous prime (51566639) and next prime (51566653).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10881 + ... + 14883.

It is an arithmetic number, because the mean of its divisors is an integer number (3423420).

Almost surely, 2^51566646 is an apocalyptic number.

51566646 is an abundant number, since it is smaller than the sum of its proper divisors (57982794).

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

51566646 is a wasteful number, since it uses less digits than its factorization.

51566646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4140.

The product of its digits is 129600, while the sum is 39.

The square root of 51566646 is about 7180.9919927542. The cubic root of 51566646 is about 372.2113638706.

It can be divided in two parts, 515 and 66646, that added together give a triangular number (67161 = T₃₆₆).

The spelling of 51566646 in words is "fifty-one million, five hundred sixty-six thousand, six hundred forty-six".