18916897657 has 8 divisors (see below), whose sum is σ = 21628123200. Its totient is φ = 16207875024.

The previous prime is 18916897651. The next prime is 18916897661. The reversal of 18916897657 is 75679861981.

It is a happy number.

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-18916897657 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18916897592 and 18916897601.

It is not an unprimeable number, because it can be changed into a prime (18916897651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 532282 + ... + 566707.

It is an arithmetic number, because the mean of its divisors is an integer number (2703515400).

Almost surely, 2^18916897657 is an apocalyptic number.

It is an amenable number.

18916897657 is a deficient number, since it is larger than the sum of its proper divisors (2711225543).

18916897657 is a wasteful number, since it uses less digits than its factorization.

18916897657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101455.

The product of its digits is 45722880, while the sum is 67.

The spelling of 18916897657 in words is "eighteen billion, nine hundred sixteen million, eight hundred ninety-seven thousand, six hundred fifty-seven".