51686964 has 72 divisors (see below), whose sum is σ = 155897280. Its totient is φ = 14766192.

The previous prime is 51686963. The next prime is 51686977. The reversal of 51686964 is 46968615.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51686963) 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, 409 + ... + 10175.

It is an arithmetic number, because the mean of its divisors is an integer number (2165240).

Almost surely, 2^51686964 is an apocalyptic number.

51686964 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 51686964, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77948640).

51686964 is an abundant number, since it is smaller than the sum of its proper divisors (104210316).

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

51686964 is a wasteful number, since it uses less digits than its factorization.

51686964 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9794 (or 9779 counting only the distinct ones).

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

The square root of 51686964 is about 7189.3646450851. The cubic root of 51686964 is about 372.5006266974.

It can be divided in two parts, 51686 and 964, that added together give a triangular number (52650 = T₃₂₄).

The spelling of 51686964 in words is "fifty-one million, six hundred eighty-six thousand, nine hundred sixty-four".