621660068 has 6 divisors (see below), whose sum is σ = 1087905126. Its totient is φ = 310830032.

The previous prime is 621660041. The next prime is 621660079. The reversal of 621660068 is 860066126.

It can be written as a sum of positive squares in only one way, i.e., 444450724 + 177209344 = 21082^2 + 13312^2 .

It is a super-2 number, since 2×621660068² = 772922480291529248, 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, 77707505 + ... + 77707512.

It is an arithmetic number, because the mean of its divisors is an integer number (181317521).

Almost surely, 2^621660068 is an apocalyptic number.

It is an amenable number.

621660068 is a deficient number, since it is larger than the sum of its proper divisors (466245058).

621660068 is a wasteful number, since it uses less digits than its factorization.

621660068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155415021 (or 155415019 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 621660068 is about 24933.1118795870. Note that the first 3 decimals coincide. The cubic root of 621660068 is about 853.4622647932.

The spelling of 621660068 in words is "six hundred twenty-one million, six hundred sixty thousand, sixty-eight".