51656642 has 8 divisors (see below), whose sum is σ = 82042956. Its totient is φ = 24308992.

The previous prime is 51656641. The next prime is 51656651. The reversal of 51656642 is 24665615.

It can be written as a sum of positive squares in 2 ways, for example, as 51136801 + 519841 = 7151^2 + 721^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (51656641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 759623 + ... + 759690.

Almost surely, 2^51656642 is an apocalyptic number.

51656642 is a deficient number, since it is larger than the sum of its proper divisors (30386314).

51656642 is a wasteful number, since it uses less digits than its factorization.

51656642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1519332.

The product of its digits is 43200, while the sum is 35.

The square root of 51656642 is about 7187.2555262771. The cubic root of 51656642 is about 372.4277703292.

The spelling of 51656642 in words is "fifty-one million, six hundred fifty-six thousand, six hundred forty-two".