51556869 has 108 divisors (see below), whose sum is σ = 103262796. Its totient is φ = 24482304.

The previous prime is 51556859. The next prime is 51556919. The reversal of 51556869 is 96865515.

It is a happy number.

51556869 is a `hidden beast` number, since 515 + 56 + 86 + 9 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 23328900 + 28227969 = 4830^2 + 5313^2 .

It is not a de Polignac number, because 51556869 - 2⁴ = 51556853 is a prime.

It is a super-2 number, since 2×51556869² = 5316221482166322, which contains 22 as substring.

Its product of digits (324000) is a multiple of the sum of its prime factors (96).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51556829) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 2241592 + ... + 2241614.

It is an arithmetic number, because the mean of its divisors is an integer number (956137).

Almost surely, 2^51556869 is an apocalyptic number.

It is an amenable number.

51556869 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

51556869 is a wasteful number, since it uses less digits than its factorization.

51556869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 63 counting only the distinct ones).

The product of its digits is 324000, while the sum is 45.

The square root of 51556869 is about 7180.3112049548. The cubic root of 51556869 is about 372.1878387124.

It can be divided in two parts, 51556 and 869, that added together give a palindrome (52425).

The spelling of 51556869 in words is "fifty-one million, five hundred fifty-six thousand, eight hundred sixty-nine".