51902921 has 16 divisors (see below), whose sum is σ = 63613440. Its totient is φ = 41333760.

The previous prime is 51902909. The next prime is 51902923. The reversal of 51902921 is 12920915.

51902921 = 1219² + 1220² + ... + 1252².

It is a cyclic number.

It is not a de Polignac number, because 51902921 - 2¹⁰ = 51901897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (51902923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6641 + ... + 12161.

It is an arithmetic number, because the mean of its divisors is an integer number (3975840).

Almost surely, 2^51902921 is an apocalyptic number.

It is an amenable number.

51902921 is a deficient number, since it is larger than the sum of its proper divisors (11710519).

51902921 is a wasteful number, since it uses less digits than its factorization.

51902921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5624.

The product of its (nonzero) digits is 1620, while the sum is 29.

The square root of 51902921 is about 7204.3681888143. The cubic root of 51902921 is about 373.0186963390.

The spelling of 51902921 in words is "fifty-one million, nine hundred two thousand, nine hundred twenty-one".