66391008 has 24 divisors (see below), whose sum is σ = 174276648. Its totient is φ = 22130304.

The previous prime is 66390991. The next prime is 66391079. The reversal of 66391008 is 80019366.

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 66391008.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 345691 + ... + 345882.

It is an arithmetic number, because the mean of its divisors is an integer number (7261527).

Almost surely, 2^66391008 is an apocalyptic number.

It is an amenable number.

66391008 is an abundant number, since it is smaller than the sum of its proper divisors (107885640).

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

66391008 is a wasteful number, since it uses less digits than its factorization.

66391008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 691586 (or 691578 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 33.

The square root of 66391008 is about 8148.0677464047. The cubic root of 66391008 is about 404.9204904121.

The spelling of 66391008 in words is "sixty-six million, three hundred ninety-one thousand, eight".