51721488 has 120 divisors (see below), whose sum is σ = 178196928. Its totient is φ = 13637376.

The previous prime is 51721487. The next prime is 51721499. The reversal of 51721488 is 88412715.

51721488 is a `hidden beast` number, since 5 + 172 + 1 + 488 = 666.

It is a super-2 number, since 2×51721488² = 5350224641868288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (51721487) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11131 + ... + 15077.

Almost surely, 2^51721488 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51721488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89098464).

51721488 is an abundant number, since it is smaller than the sum of its proper divisors (126475440).

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

51721488 is a wasteful number, since it uses less digits than its factorization.

51721488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3981 (or 3972 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 51721488 is about 7191.7652909421. The cubic root of 51721488 is about 372.5835447642.

The spelling of 51721488 in words is "fifty-one million, seven hundred twenty-one thousand, four hundred eighty-eight".