621669918 has 16 divisors (see below), whose sum is σ = 1248819840. Its totient is φ = 206309976.

The previous prime is 621669887. The next prime is 621669929. The reversal of 621669918 is 819966126.

It is a super-2 number, since 2×621669918² = 772946973892253448, which contains 22 as substring.

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, 226858 + ... + 229581.

It is an arithmetic number, because the mean of its divisors is an integer number (78051240).

Almost surely, 2^621669918 is an apocalyptic number.

621669918 is an abundant number, since it is smaller than the sum of its proper divisors (627149922).

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

621669918 is a wasteful number, since it uses less digits than its factorization.

621669918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 456671.

The product of its digits is 279936, while the sum is 48.

The square root of 621669918 is about 24933.3094072969. The cubic root of 621669918 is about 853.4667723793.

The spelling of 621669918 in words is "six hundred twenty-one million, six hundred sixty-nine thousand, nine hundred eighteen".