51721880 has 32 divisors (see below), whose sum is σ = 132999840. Its totient is φ = 17733120.

The previous prime is 51721861. The next prime is 51721897. The reversal of 51721880 is 8812715.

It is a happy number.

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, 92081 + ... + 92640.

It is an arithmetic number, because the mean of its divisors is an integer number (4156245).

Almost surely, 2^51721880 is an apocalyptic number.

It is an amenable number.

51721880 is an abundant number, since it is smaller than the sum of its proper divisors (81277960).

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

51721880 is a wasteful number, since it uses less digits than its factorization.

51721880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184739 (or 184735 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 51721880 is about 7191.7925442827. The cubic root of 51721880 is about 372.5844860389.

The spelling of 51721880 in words is "fifty-one million, seven hundred twenty-one thousand, eight hundred eighty".