667813680 has 80 divisors (see below), whose sum is σ = 2300254560. Its totient is φ = 178083072.

The previous prime is 667813673. The next prime is 667813697. The reversal of 667813680 is 86318766.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×667813680² = 891950222390284800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152427 + ... + 156746.

It is an arithmetic number, because the mean of its divisors is an integer number (28753182).

Almost surely, 2^667813680 is an apocalyptic number.

667813680 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

667813680 is an abundant number, since it is smaller than the sum of its proper divisors (1632440880).

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

667813680 is a wasteful number, since it uses less digits than its factorization.

667813680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 309195 (or 309183 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 45.

The square root of 667813680 is about 25842.0912466464. The cubic root of 667813680 is about 874.0811819018.

The spelling of 667813680 in words is "six hundred sixty-seven million, eight hundred thirteen thousand, six hundred eighty".