51863121 has 12 divisors (see below), whose sum is σ = 74976772. Its totient is φ = 34546176.

The previous prime is 51863101. The next prime is 51863129. The reversal of 51863121 is 12136815.

51863121 is a `hidden beast` number, since 5 + 1 + 8 + 631 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 39690000 + 12173121 = 6300^2 + 3489^2 .

It is not a de Polignac number, because 51863121 - 2⁵ = 51863089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51863129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16725 + ... + 19581.

Almost surely, 2^51863121 is an apocalyptic number.

It is an amenable number.

51863121 is a deficient number, since it is larger than the sum of its proper divisors (23113651).

51863121 is a wasteful number, since it uses less digits than its factorization.

51863121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4880 (or 4877 counting only the distinct ones).

The product of its digits is 1440, while the sum is 27.

The square root of 51863121 is about 7201.6054460099. The cubic root of 51863121 is about 372.9233263662.

Adding to 51863121 its reverse (12136815), we get a palindrome (63999936).

It can be divided in two parts, 51863 and 121, that added together give a square (51984 = 228²).

The spelling of 51863121 in words is "fifty-one million, eight hundred sixty-three thousand, one hundred twenty-one".