621900981 has 24 divisors (see below), whose sum is σ = 968263296. Its totient is φ = 382367520.

The previous prime is 621900971. The next prime is 621901003. The reversal of 621900981 is 189009126.

It is not a de Polignac number, because 621900981 - 2⁵ = 621900949 is a prime.

It is a super-2 number, since 2×621900981² = 773521660337524722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621900931) 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, 212776 + ... + 215678.

It is an arithmetic number, because the mean of its divisors is an integer number (40344304).

Almost surely, 2^621900981 is an apocalyptic number.

It is an amenable number.

621900981 is a deficient number, since it is larger than the sum of its proper divisors (346362315).

621900981 is a wasteful number, since it uses less digits than its factorization.

621900981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4753 (or 4750 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 621900981 is about 24937.9425975761. The cubic root of 621900981 is about 853.5724984567.

The spelling of 621900981 in words is "six hundred twenty-one million, nine hundred thousand, nine hundred eighty-one".