51928021 has 4 divisors (see below), whose sum is σ = 51946272. Its totient is φ = 51909772.

The previous prime is 51927973. The next prime is 51928027. The reversal of 51928021 is 12082915.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 51928021 - 2²³ = 43539413 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51928027) 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, 3835 + ... + 10888.

It is an arithmetic number, because the mean of its divisors is an integer number (12986568).

Almost surely, 2^51928021 is an apocalyptic number.

It is an amenable number.

51928021 is a deficient number, since it is larger than the sum of its proper divisors (18251).

51928021 is a wasteful number, since it uses less digits than its factorization.

51928021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18250.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 51928021 is about 7206.1099769571. The cubic root of 51928021 is about 373.0788166575.

The spelling of 51928021 in words is "fifty-one million, nine hundred twenty-eight thousand, twenty-one".