51239616 has 56 divisors (see below), whose sum is σ = 136940544. Its totient is φ = 16907520.

The previous prime is 51239609. The next prime is 51239647. The reversal of 51239616 is 61693215.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18481 + ... + 21071.

Almost surely, 2^51239616 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 51239616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68470272).

51239616 is an abundant number, since it is smaller than the sum of its proper divisors (85700928).

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

51239616 is a wasteful number, since it uses less digits than its factorization.

51239616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2709 (or 2699 counting only the distinct ones).

The product of its digits is 9720, while the sum is 33.

The square root of 51239616 is about 7158.1852448788. The cubic root of 51239616 is about 371.4228534482.

The spelling of 51239616 in words is "fifty-one million, two hundred thirty-nine thousand, six hundred sixteen".