51636816 has 120 divisors (see below), whose sum is σ = 180208704. Its totient is φ = 13409280.

The previous prime is 51636811. The next prime is 51636839. The reversal of 51636816 is 61863615.

It is a happy number.

51636816 is a `hidden beast` number, since 5 + 1 + 636 + 8 + 16 = 666.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51636811) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8760 + ... + 13416.

Almost surely, 2^51636816 is an apocalyptic number.

51636816 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51636816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90104352).

51636816 is an abundant number, since it is smaller than the sum of its proper divisors (128571888).

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

51636816 is a wasteful number, since it uses less digits than its factorization.

51636816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4689 (or 4680 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 51636816 is about 7185.8761469984. The cubic root of 51636816 is about 372.3801178717.

The spelling of 51636816 in words is "fifty-one million, six hundred thirty-six thousand, eight hundred sixteen".