51642561 has 8 divisors (see below), whose sum is σ = 69359904. Its totient is φ = 34176800.

The previous prime is 51642529. The next prime is 51642581. The reversal of 51642561 is 16524615.

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

It is a cyclic number.

It is not a de Polignac number, because 51642561 - 2⁵ = 51642529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (51642581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62415 + ... + 63236.

It is an arithmetic number, because the mean of its divisors is an integer number (8669988).

Almost surely, 2^51642561 is an apocalyptic number.

It is an amenable number.

51642561 is a deficient number, since it is larger than the sum of its proper divisors (17717343).

51642561 is a wasteful number, since it uses less digits than its factorization.

51642561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125791.

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

The square root of 51642561 is about 7186.2758783670. The cubic root of 51642561 is about 372.3939274273.

The spelling of 51642561 in words is "fifty-one million, six hundred forty-two thousand, five hundred sixty-one".