51561642 has 32 divisors (see below), whose sum is σ = 112777920. Its totient is φ = 15585920.

The previous prime is 51561637. The next prime is 51561673. The reversal of 51561642 is 24616515.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36868 + ... + 38240.

It is an arithmetic number, because the mean of its divisors is an integer number (3524310).

Almost surely, 2^51561642 is an apocalyptic number.

51561642 is an abundant number, since it is smaller than the sum of its proper divisors (61216278).

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

51561642 is a wasteful number, since it uses less digits than its factorization.

51561642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1958.

The product of its digits is 7200, while the sum is 30.

The square root of 51561642 is about 7180.6435644725. The cubic root of 51561642 is about 372.1993237500.

The spelling of 51561642 in words is "fifty-one million, five hundred sixty-one thousand, six hundred forty-two".