621253664 has 12 divisors (see below), whose sum is σ = 1223093214. Its totient is φ = 310626816.

The previous prime is 621253649. The next prime is 621253673. The reversal of 621253664 is 466352126.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 600642064 + 20611600 = 24508^2 + 4540^2 .

It is a super-2 number, since 2×621253664² = 771912230066849792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9707057 + ... + 9707120.

Almost surely, 2^621253664 is an apocalyptic number.

It is an amenable number.

621253664 is a deficient number, since it is larger than the sum of its proper divisors (601839550).

621253664 is a wasteful number, since it uses less digits than its factorization.

621253664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19414187 (or 19414179 counting only the distinct ones).

The product of its digits is 51840, while the sum is 35.

The square root of 621253664 is about 24924.9606619549. The cubic root of 621253664 is about 853.2762434680.

The spelling of 621253664 in words is "six hundred twenty-one million, two hundred fifty-three thousand, six hundred sixty-four".