660993997 has 8 divisors (see below), whose sum is σ = 683950592. Its totient is φ = 638139600.

The previous prime is 660993967. The next prime is 660994043. The reversal of 660993997 is 799399066.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-660993997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660993917) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12273 + ... + 38374.

It is an arithmetic number, because the mean of its divisors is an integer number (85493824).

Almost surely, 2^660993997 is an apocalyptic number.

It is an amenable number.

660993997 is a deficient number, since it is larger than the sum of its proper divisors (22956595).

660993997 is a wasteful number, since it uses less digits than its factorization.

660993997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51099.

The product of its (nonzero) digits is 4960116, while the sum is 58.

The square root of 660993997 is about 25709.8035192803. The cubic root of 660993997 is about 871.0956368469.

The spelling of 660993997 in words is "six hundred sixty million, nine hundred ninety-three thousand, nine hundred ninety-seven".