621404554 has 4 divisors (see below), whose sum is σ = 932106834. Its totient is φ = 310702276.

The previous prime is 621404527. The next prime is 621404561. The reversal of 621404554 is 455404126.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 378886225 + 242518329 = 19465^2 + 15573^2 .

It is a super-2 number, since 2×621404554² = 772287239463877832, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 155351137 + ... + 155351140.

Almost surely, 2^621404554 is an apocalyptic number.

621404554 is a deficient number, since it is larger than the sum of its proper divisors (310702280).

621404554 is a wasteful number, since it uses less digits than its factorization.

621404554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310702279.

The product of its (nonzero) digits is 19200, while the sum is 31.

The square root of 621404554 is about 24927.9873636040. The cubic root of 621404554 is about 853.3453190794.

The spelling of 621404554 in words is "six hundred twenty-one million, four hundred four thousand, five hundred fifty-four".