51721716 has 24 divisors (see below), whose sum is σ = 120867264. Its totient is φ = 17214400.

The previous prime is 51721697. The next prime is 51721721. The reversal of 51721716 is 61712715.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6016 + ... + 11816.

It is an arithmetic number, because the mean of its divisors is an integer number (5036136).

Almost surely, 2^51721716 is an apocalyptic number.

It is an amenable number.

51721716 is an abundant number, since it is smaller than the sum of its proper divisors (69145548).

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

51721716 is a wasteful number, since it uses less digits than its factorization.

51721716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6551 (or 6549 counting only the distinct ones).

The product of its digits is 2940, while the sum is 30.

The square root of 51721716 is about 7191.7811423875. The cubic root of 51721716 is about 372.5840922409.

Subtracting 51721716 from its reverse (61712715), we obtain a palindrome (9990999).

The spelling of 51721716 in words is "fifty-one million, seven hundred twenty-one thousand, seven hundred sixteen".