51400644 has 24 divisors (see below), whose sum is σ = 124071360. Its totient is φ = 16542624.

The previous prime is 51400637. The next prime is 51400651. The reversal of 51400644 is 44600415.

It is an interprime number because it is at equal distance from previous prime (51400637) and next prime (51400651).

It is a super-2 number, since 2×51400644² = 5284052407229472, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 73504 + ... + 74199.

It is an arithmetic number, because the mean of its divisors is an integer number (5169640).

Almost surely, 2^51400644 is an apocalyptic number.

It is an amenable number.

51400644 is an abundant number, since it is smaller than the sum of its proper divisors (72670716).

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

51400644 is a wasteful number, since it uses less digits than its factorization.

51400644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 147739 (or 147737 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 51400644 is about 7169.4242446657. The cubic root of 51400644 is about 371.8115301513.

The spelling of 51400644 in words is "fifty-one million, four hundred thousand, six hundred forty-four".