51235921 has 4 divisors (see below), whose sum is σ = 55893744. Its totient is φ = 46578100.

The previous prime is 51235897. The next prime is 51235931. The reversal of 51235921 is 12953215.

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 51235921 - 2⁹ = 51235409 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 51235921.

It is not an unprimeable number, because it can be changed into a prime (51235931) 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, 2328895 + ... + 2328916.

It is an arithmetic number, because the mean of its divisors is an integer number (13973436).

Almost surely, 2^51235921 is an apocalyptic number.

It is an amenable number.

51235921 is a deficient number, since it is larger than the sum of its proper divisors (4657823).

51235921 is a wasteful number, since it uses less digits than its factorization.

51235921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4657822.

The product of its digits is 2700, while the sum is 28.

The square root of 51235921 is about 7157.9271440830. The cubic root of 51235921 is about 371.4139251973.

The spelling of 51235921 in words is "fifty-one million, two hundred thirty-five thousand, nine hundred twenty-one".