19887573897 has 16 divisors (see below), whose sum is σ = 29559055680. Its totient is φ = 13215190176.

The previous prime is 19887573883. The next prime is 19887573899. The reversal of 19887573897 is 79837578891.

It is a happy number.

19887573897 is a `hidden beast` number, since 198 + 8 + 7 + 57 + 389 + 7 = 666.

It is not a de Polignac number, because 19887573897 - 2¹¹ = 19887571849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (19887573899) 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, 1191348 + ... + 1207925.

It is an arithmetic number, because the mean of its divisors is an integer number (1847440980).

Almost surely, 2^19887573897 is an apocalyptic number.

It is an amenable number.

19887573897 is a deficient number, since it is larger than the sum of its proper divisors (9671481783).

19887573897 is a wasteful number, since it uses less digits than its factorization.

19887573897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2399589 (or 2399583 counting only the distinct ones).

The product of its digits is 213373440, while the sum is 72.

The spelling of 19887573897 in words is "nineteen billion, eight hundred eighty-seven million, five hundred seventy-three thousand, eight hundred ninety-seven".