621638154 has 12 divisors (see below), whose sum is σ = 1346882706. Its totient is φ = 207212712.

The previous prime is 621638117. The next prime is 621638161. The reversal of 621638154 is 451836126.

It is a happy number.

621638154 is a `hidden beast` number, since 6 + 2 + 1 + 638 + 15 + 4 = 666.

It can be written as a sum of positive squares in only one way, i.e., 454840929 + 166797225 = 21327^2 + 12915^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17267709 + ... + 17267744.

Almost surely, 2^621638154 is an apocalyptic number.

621638154 is an abundant number, since it is smaller than the sum of its proper divisors (725244552).

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

621638154 is a wasteful number, since it uses less digits than its factorization.

621638154 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34535461 (or 34535458 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 621638154 is about 24932.6724199393. The cubic root of 621638154 is about 853.4522362729.

The spelling of 621638154 in words is "six hundred twenty-one million, six hundred thirty-eight thousand, one hundred fifty-four".