51986664 has 64 divisors (see below), whose sum is σ = 145176000. Its totient is φ = 17236800.

The previous prime is 51986657. The next prime is 51986677. The reversal of 51986664 is 46668915.

It is a super-2 number, since 2×51986664² = 5405226467697792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48939 + ... + 49989.

It is an arithmetic number, because the mean of its divisors is an integer number (2268375).

Almost surely, 2^51986664 is an apocalyptic number.

51986664 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 51986664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72588000).

51986664 is an abundant number, since it is smaller than the sum of its proper divisors (93189336).

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

51986664 is a wasteful number, since it uses less digits than its factorization.

51986664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1295 (or 1285 counting only the distinct ones).

The product of its digits is 311040, while the sum is 45.

The square root of 51986664 is about 7210.1778064067. The cubic root of 51986664 is about 373.2192047685.

It can be divided in two parts, 51986 and 664, that added together give a triangular number (52650 = T₃₂₄).

The spelling of 51986664 in words is "fifty-one million, nine hundred eighty-six thousand, six hundred sixty-four".