51087213 has 8 divisors (see below), whose sum is σ = 75684800. Its totient is φ = 34058124.

The previous prime is 51087191. The next prime is 51087233. The reversal of 51087213 is 31278015.

It is not a de Polignac number, because 51087213 - 2¹⁸ = 50825069 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1892119 = 51087213 / (5 + 1 + 0 + 8 + 7 + 2 + 1 + 3).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51087233) 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, 946033 + ... + 946086.

It is an arithmetic number, because the mean of its divisors is an integer number (9460600).

Almost surely, 2^51087213 is an apocalyptic number.

It is an amenable number.

51087213 is a deficient number, since it is larger than the sum of its proper divisors (24597587).

51087213 is a wasteful number, since it uses less digits than its factorization.

51087213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1892128 (or 1892122 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 51087213 is about 7147.5319516600. The cubic root of 51087213 is about 371.0542443141.

It can be divided in two parts, 5108 and 7213, that added together give a palindrome (12321).

The spelling of 51087213 in words is "fifty-one million, eighty-seven thousand, two hundred thirteen".