668617056 has 36 divisors (see below), whose sum is σ = 1901380572. Its totient is φ = 222872256.

The previous prime is 668617013. The next prime is 668617091. The reversal of 668617056 is 650716866.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1160506 + ... + 1161081.

It is an arithmetic number, because the mean of its divisors is an integer number (52816127).

Almost surely, 2^668617056 is an apocalyptic number.

It is an amenable number.

668617056 is an abundant number, since it is smaller than the sum of its proper divisors (1232763516).

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

668617056 is a wasteful number, since it uses less digits than its factorization.

668617056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2321603 (or 2321592 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The square root of 668617056 is about 25857.6305178955. The cubic root of 668617056 is about 874.4315463150.

The spelling of 668617056 in words is "six hundred sixty-eight million, six hundred seventeen thousand, fifty-six".