659618991 has 32 divisors (see below), whose sum is σ = 1032768000. Its totient is φ = 414932544.

The previous prime is 659618987. The next prime is 659619013. The reversal of 659618991 is 199816956.

It is not a de Polignac number, because 659618991 - 2² = 659618987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (659618951) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 132475 + ... + 137363.

It is an arithmetic number, because the mean of its divisors is an integer number (32274000).

Almost surely, 2^659618991 is an apocalyptic number.

659618991 is a deficient number, since it is larger than the sum of its proper divisors (373149009).

659618991 is a wasteful number, since it uses less digits than its factorization.

659618991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5180 (or 5174 counting only the distinct ones).

The product of its digits is 1049760, while the sum is 54.

The square root of 659618991 is about 25683.0487092167. The cubic root of 659618991 is about 870.4911970559.

The spelling of 659618991 in words is "six hundred fifty-nine million, six hundred eighteen thousand, nine hundred ninety-one".