51686990 has 16 divisors (see below), whose sum is σ = 96245280. Its totient is φ = 19961760.

The previous prime is 51686977. The next prime is 51687023. The reversal of 51686990 is 9968615.

51686990 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88826 + ... + 89405.

It is an arithmetic number, because the mean of its divisors is an integer number (6015330).

Almost surely, 2^51686990 is an apocalyptic number.

51686990 is a deficient number, since it is larger than the sum of its proper divisors (44558290).

51686990 is a wasteful number, since it uses less digits than its factorization.

51686990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178267.

The product of its (nonzero) digits is 116640, while the sum is 44.

The square root of 51686990 is about 7189.3664533114. The cubic root of 51686990 is about 372.5006891569.

The spelling of 51686990 in words is "fifty-one million, six hundred eighty-six thousand, nine hundred ninety".