51993865 has 16 divisors (see below), whose sum is σ = 77788800. Its totient is φ = 32411520.

The previous prime is 51993859. The next prime is 51993881. The reversal of 51993865 is 56839915.

It is not a de Polignac number, because 51993865 - 2⁵ = 51993833 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67140 + ... + 67909.

It is an arithmetic number, because the mean of its divisors is an integer number (4861800).

Almost surely, 2^51993865 is an apocalyptic number.

51993865 is a gapful number since it is divisible by the number (55) formed by its first and last digit.

It is an amenable number.

51993865 is a deficient number, since it is larger than the sum of its proper divisors (25794935).

51993865 is a wasteful number, since it uses less digits than its factorization.

51993865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 135072.

The product of its digits is 291600, while the sum is 46.

The square root of 51993865 is about 7210.6771526674. The cubic root of 51993865 is about 373.2364362865.

The spelling of 51993865 in words is "fifty-one million, nine hundred ninety-three thousand, eight hundred sixty-five".