625221621 has 12 divisors (see below), whose sum is σ = 904670572. Its totient is φ = 416088576.

The previous prime is 625221617. The next prime is 625221629. The reversal of 625221621 is 126122526.

625221621 is a `hidden beast` number, since 625 + 2 + 2 + 16 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 584962596 + 40259025 = 24186^2 + 6345^2 .

It is not a de Polignac number, because 625221621 - 2² = 625221617 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (625221629) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 55006 + ... + 65391.

Almost surely, 2^625221621 is an apocalyptic number.

It is an amenable number.

625221621 is a deficient number, since it is larger than the sum of its proper divisors (279448951).

625221621 is a wasteful number, since it uses less digits than its factorization.

625221621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120980 (or 120977 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 625221621 is about 25004.4320271427. The cubic root of 625221621 is about 855.0890191504.

The spelling of 625221621 in words is "six hundred twenty-five million, two hundred twenty-one thousand, six hundred twenty-one".