51532721 has 8 divisors (see below), whose sum is σ = 52227840. Its totient is φ = 50842512.

The previous prime is 51532717. The next prime is 51532781. The reversal of 51532721 is 12723515.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 51532721 - 2² = 51532717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51532711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22976 + ... + 25118.

It is an arithmetic number, because the mean of its divisors is an integer number (6528480).

Almost surely, 2^51532721 is an apocalyptic number.

It is an amenable number.

51532721 is a deficient number, since it is larger than the sum of its proper divisors (695119).

51532721 is a wasteful number, since it uses less digits than its factorization.

51532721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2455.

The product of its digits is 2100, while the sum is 26.

The square root of 51532721 is about 7178.6294652949. The cubic root of 51532721 is about 372.1297216877.

The spelling of 51532721 in words is "fifty-one million, five hundred thirty-two thousand, seven hundred twenty-one".