621986128 has 40 divisors (see below), whose sum is σ = 1286435520. Its totient is φ = 290465280.

The previous prime is 621986119. The next prime is 621986149. The reversal of 621986128 is 821689126.

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, 7176 + ... + 35992.

It is an arithmetic number, because the mean of its divisors is an integer number (32160888).

Almost surely, 2^621986128 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 621986128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (643217760).

621986128 is an abundant number, since it is smaller than the sum of its proper divisors (664449392).

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

621986128 is a wasteful number, since it uses less digits than its factorization.

621986128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28915 (or 28909 counting only the distinct ones).

The product of its digits is 82944, while the sum is 43.

The square root of 621986128 is about 24939.6497168665. The cubic root of 621986128 is about 853.6114520431.

The spelling of 621986128 in words is "six hundred twenty-one million, nine hundred eighty-six thousand, one hundred twenty-eight".