997890659 has 16 divisors (see below), whose sum is σ = 1070496000. Its totient is φ = 927364320.

The previous prime is 997890653. The next prime is 997890671. The reversal of 997890659 is 956098799.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-997890659 is a prime.

It is not an unprimeable number, because it can be changed into a prime (997890653) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 939989 + ... + 941049.

It is an arithmetic number, because the mean of its divisors is an integer number (66906000).

Almost surely, 2^997890659 is an apocalyptic number.

997890659 is a deficient number, since it is larger than the sum of its proper divisors (72605341).

997890659 is a wasteful number, since it uses less digits than its factorization.

With its successor (997890660) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (1978).

997890659 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1978.

The product of its (nonzero) digits is 11022480, while the sum is 62.

The square root of 997890659 is about 31589.4073860210. The cubic root of 997890659 is about 999.2963913844.

The spelling of 997890659 in words is "nine hundred ninety-seven million, eight hundred ninety thousand, six hundred fifty-nine".