51720894 has 24 divisors (see below), whose sum is σ = 115092120. Its totient is φ = 16774128.

The previous prime is 51720883. The next prime is 51720901. The reversal of 51720894 is 49802715.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38164 + ... + 39495.

It is an arithmetic number, because the mean of its divisors is an integer number (4795505).

Almost surely, 2^51720894 is an apocalyptic number.

51720894 is an abundant number, since it is smaller than the sum of its proper divisors (63371226).

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

51720894 is a wasteful number, since it uses less digits than its factorization.

51720894 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77704 (or 77701 counting only the distinct ones).

The product of its (nonzero) digits is 20160, while the sum is 36.

The square root of 51720894 is about 7191.7239935915. The cubic root of 51720894 is about 372.5821184359.

The spelling of 51720894 in words is "fifty-one million, seven hundred twenty thousand, eight hundred ninety-four".