51930921 has 32 divisors (see below), whose sum is σ = 82272256. Its totient is φ = 28512000.

The previous prime is 51930881. The next prime is 51930929. The reversal of 51930921 is 12903915.

It is not a de Polignac number, because 51930921 - 2¹⁴ = 51914537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51930929) 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, 156726 + ... + 157056.

It is an arithmetic number, because the mean of its divisors is an integer number (2571008).

Almost surely, 2^51930921 is an apocalyptic number.

It is an amenable number.

51930921 is a deficient number, since it is larger than the sum of its proper divisors (30341335).

51930921 is a wasteful number, since it uses less digits than its factorization.

51930921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 613.

The product of its (nonzero) digits is 2430, while the sum is 30.

The square root of 51930921 is about 7206.3111922814. The cubic root of 51930921 is about 373.0857615811.

The spelling of 51930921 in words is "fifty-one million, nine hundred thirty thousand, nine hundred twenty-one".