18205257897 has 16 divisors (see below), whose sum is σ = 27036712000. Its totient is φ = 12107156832.

The previous prime is 18205257871. The next prime is 18205257899. The reversal of 18205257897 is 79875250281.

18205257897 is a `hidden beast` number, since 1 + 8 + 20 + 525 + 7 + 8 + 97 = 666.

It is not a de Polignac number, because 18205257897 - 2²³ = 18196869289 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18205257899) 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, 813247 + ... + 835332.

It is an arithmetic number, because the mean of its divisors is an integer number (1689794500).

Almost surely, 2^18205257897 is an apocalyptic number.

It is an amenable number.

18205257897 is a deficient number, since it is larger than the sum of its proper divisors (8831454103).

18205257897 is a wasteful number, since it uses less digits than its factorization.

18205257897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1648997 (or 1648991 counting only the distinct ones).

The product of its (nonzero) digits is 2822400, while the sum is 54.

The spelling of 18205257897 in words is "eighteen billion, two hundred five million, two hundred fifty-seven thousand, eight hundred ninety-seven".