667921068 has 36 divisors (see below), whose sum is σ = 1690547040. Its totient is φ = 222351456.

The previous prime is 667921049. The next prime is 667921073. The reversal of 667921068 is 860129766.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-2 number, since 2×667921068² = 892237106156521248, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 17053 + ... + 40331.

It is an arithmetic number, because the mean of its divisors is an integer number (46959640).

Almost surely, 2^667921068 is an apocalyptic number.

It is an amenable number.

667921068 is an abundant number, since it is smaller than the sum of its proper divisors (1022625972).

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

667921068 is a wasteful number, since it uses less digits than its factorization.

667921068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24086 (or 24081 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The square root of 667921068 is about 25844.1689361450. The cubic root of 667921068 is about 874.1280316953.

The spelling of 667921068 in words is "six hundred sixty-seven million, nine hundred twenty-one thousand, sixty-eight".