51804921 has 32 divisors (see below), whose sum is σ = 82478848. Its totient is φ = 28304640.

The previous prime is 51804913. The next prime is 51804953. The reversal of 51804921 is 12940815.

It is a happy number.

It is not a de Polignac number, because 51804921 - 2³ = 51804913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51804971) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 46851 + ... + 47943.

It is an arithmetic number, because the mean of its divisors is an integer number (2577464).

Almost surely, 2^51804921 is an apocalyptic number.

It is an amenable number.

51804921 is a deficient number, since it is larger than the sum of its proper divisors (30673927).

51804921 is a wasteful number, since it uses less digits than its factorization.

51804921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1201.

The product of its (nonzero) digits is 2880, while the sum is 30.

The square root of 51804921 is about 7197.5635460897. The cubic root of 51804921 is about 372.7837778719.

It can be divided in two parts, 51804 and 921, that added together give a palindrome (52725).

The spelling of 51804921 in words is "fifty-one million, eight hundred four thousand, nine hundred twenty-one".