621553998 has 16 divisors (see below), whose sum is σ = 1338731856. Its totient is φ = 191247360.

The previous prime is 621553979. The next prime is 621554027. The reversal of 621553998 is 899355126.

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, 3984243 + ... + 3984398.

It is an arithmetic number, because the mean of its divisors is an integer number (83670741).

Almost surely, 2^621553998 is an apocalyptic number.

621553998 is an abundant number, since it is smaller than the sum of its proper divisors (717177858).

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

621553998 is a wasteful number, since it uses less digits than its factorization.

621553998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7968659.

The product of its digits is 583200, while the sum is 48.

The square root of 621553998 is about 24930.9846977611. The cubic root of 621553998 is about 853.4137217087.

The spelling of 621553998 in words is "six hundred twenty-one million, five hundred fifty-three thousand, nine hundred ninety-eight".