18890821715 has 16 divisors (see below), whose sum is σ = 22785235200. Its totient is φ = 15035246592.

The previous prime is 18890821711. The next prime is 18890821717. The reversal of 18890821715 is 51712809881.

It is a cyclic number.

It is not a de Polignac number, because 18890821715 - 2² = 18890821711 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18890821711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2101751 + ... + 2110719.

It is an arithmetic number, because the mean of its divisors is an integer number (1424077200).

Almost surely, 2^18890821715 is an apocalyptic number.

18890821715 is a deficient number, since it is larger than the sum of its proper divisors (3894413485).

18890821715 is a wasteful number, since it uses less digits than its factorization.

18890821715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11086.

The product of its (nonzero) digits is 322560, while the sum is 50.

The spelling of 18890821715 in words is "eighteen billion, eight hundred ninety million, eight hundred twenty-one thousand, seven hundred fifteen".