51978644 has 12 divisors (see below), whose sum is σ = 91768404. Its totient is φ = 25759104.

The previous prime is 51978629. The next prime is 51978653. The reversal of 51978644 is 44687915.

It can be written as a sum of positive squares in 2 ways, for example, as 5466244 + 46512400 = 2338^2 + 6820^2 .

It is a junction number, because it is equal to n+sod(n) for n = 51978595 and 51978604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57047 + ... + 57950.

It is an arithmetic number, because the mean of its divisors is an integer number (7647367).

Almost surely, 2^51978644 is an apocalyptic number.

It is an amenable number.

51978644 is a deficient number, since it is larger than the sum of its proper divisors (39789760).

51978644 is a wasteful number, since it uses less digits than its factorization.

51978644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115114 (or 115112 counting only the distinct ones).

The product of its digits is 241920, while the sum is 44.

The square root of 51978644 is about 7209.6216266875. The cubic root of 51978644 is about 373.2000115644.

The spelling of 51978644 in words is "fifty-one million, nine hundred seventy-eight thousand, six hundred forty-four".