51993491 has 8 divisors (see below), whose sum is σ = 58676400. Its totient is φ = 45636640.

The previous prime is 51993457. The next prime is 51993499. The reversal of 51993491 is 19439915.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51993491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (51993499) 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, 81176 + ... + 81813.

It is an arithmetic number, because the mean of its divisors is an integer number (7334550).

Almost surely, 2^51993491 is an apocalyptic number.

51993491 is a deficient number, since it is larger than the sum of its proper divisors (6682909).

51993491 is a wasteful number, since it uses less digits than its factorization.

51993491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163029.

The product of its digits is 43740, while the sum is 41.

The square root of 51993491 is about 7210.6512188567. The cubic root of 51993491 is about 373.2355413683.

It can be divided in two parts, 519934 and 91, that added together give a palindrome (520025).

The spelling of 51993491 in words is "fifty-one million, nine hundred ninety-three thousand, four hundred ninety-one".