51657321 has 8 divisors (see below), whose sum is σ = 69059680. Its totient is φ = 34346592.

The previous prime is 51657317. The next prime is 51657329. The reversal of 51657321 is 12375615.

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

It is not a de Polignac number, because 51657321 - 2² = 51657317 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51657329) 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, 21580 + ... + 23853.

It is an arithmetic number, because the mean of its divisors is an integer number (8632460).

Almost surely, 2^51657321 is an apocalyptic number.

It is an amenable number.

51657321 is a deficient number, since it is larger than the sum of its proper divisors (17402359).

51657321 is a wasteful number, since it uses less digits than its factorization.

51657321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45815.

The product of its digits is 6300, while the sum is 30.

The square root of 51657321 is about 7187.3027625111. The cubic root of 51657321 is about 372.4294021126.

The spelling of 51657321 in words is "fifty-one million, six hundred fifty-seven thousand, three hundred twenty-one".