51365664 has 240 divisors, whose sum is σ = 182952000. Its totient is φ = 13810176.

The previous prime is 51365663. The next prime is 51365707. The reversal of 51365664 is 46656315.

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).

Its product of digits (64800) is a multiple of the sum of its prime divisors (180).

It is not an unprimeable number, because it can be changed into a prime (51365663) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 344662 + ... + 344810.

It is an arithmetic number, because the mean of its divisors is an integer number (762300).

Almost surely, 2^51365664 is an apocalyptic number.

51365664 is a gapful number since it is divisible by the number (54) 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 51365664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (91476000).

51365664 is an abundant number, since it is smaller than the sum of its proper divisors (131586336).

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

51365664 is a wasteful number, since it uses less digits than its factorization.

51365664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197 (or 180 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 51365664 is about 7166.9843030385. The cubic root of 51365664 is about 371.7271672733.

The spelling of 51365664 in words is "fifty-one million, three hundred sixty-five thousand, six hundred sixty-four".