51397881 has 8 divisors (see below), whose sum is σ = 68914080. Its totient is φ = 34073472.

The previous prime is 51397877. The next prime is 51397883. The reversal of 51397881 is 18879315.

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

It is not a de Polignac number, because 51397881 - 2² = 51397877 is a prime.

It is a super-2 number, since 2×51397881² = 5283484342580322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (51397883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47320 + ... + 48393.

It is an arithmetic number, because the mean of its divisors is an integer number (8614260).

Almost surely, 2^51397881 is an apocalyptic number.

It is an amenable number.

51397881 is a deficient number, since it is larger than the sum of its proper divisors (17516199).

51397881 is a wasteful number, since it uses less digits than its factorization.

51397881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95895.

The product of its digits is 60480, while the sum is 42.

The square root of 51397881 is about 7169.2315487784. The cubic root of 51397881 is about 371.8048678894.

The spelling of 51397881 in words is "fifty-one million, three hundred ninety-seven thousand, eight hundred eighty-one".