51733921 has 4 divisors (see below), whose sum is σ = 51750532. Its totient is φ = 51717312.

The previous prime is 51733919. The next prime is 51733931. The reversal of 51733921 is 12933715.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 17640000 + 34093921 = 4200^2 + 5839^2 .

It is a 3-Lehmer number, since φ(51733921) divides (51733921-1)³.

It is a cyclic number.

It is not a de Polignac number, because 51733921 - 2¹ = 51733919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51733901) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2076 + ... + 10381.

It is an arithmetic number, because the mean of its divisors is an integer number (12937633).

Almost surely, 2^51733921 is an apocalyptic number.

51733921 is the 4153-rd octagonal number.

It is an amenable number.

51733921 is a deficient number, since it is larger than the sum of its proper divisors (16611).

51733921 is a wasteful number, since it uses less digits than its factorization.

51733921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16610.

The product of its digits is 5670, while the sum is 31.

The square root of 51733921 is about 7192.6296303925. The cubic root of 51733921 is about 372.6133967030.

The spelling of 51733921 in words is "fifty-one million, seven hundred thirty-three thousand, nine hundred twenty-one".