51345864 has 48 divisors (see below), whose sum is σ = 140981100. Its totient is φ = 16879104.

The previous prime is 51345859. The next prime is 51345893. The reversal of 51345864 is 46854315.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 51236964 + 108900 = 7158^2 + 330^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 372 + ... + 10140.

Almost surely, 2^51345864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51345864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (70490550).

51345864 is an abundant number, since it is smaller than the sum of its proper divisors (89635236).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51345864 is a wasteful number, since it uses less digits than its factorization.

51345864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9854 (or 9847 counting only the distinct ones).

The product of its digits is 57600, while the sum is 36.

The square root of 51345864 is about 7165.6028357703. The cubic root of 51345864 is about 371.6793977242.

The spelling of 51345864 in words is "fifty-one million, three hundred forty-five thousand, eight hundred sixty-four".