19890398902 has 24 divisors (see below), whose sum is σ = 32801735736. Its totient is φ = 9039096000.

The previous prime is 19890398897. The next prime is 19890398909. The reversal of 19890398902 is 20989309891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19890398909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2183377 + ... + 2192467.

It is an arithmetic number, because the mean of its divisors is an integer number (1366738989).

Almost surely, 2^19890398902 is an apocalyptic number.

19890398902 is a deficient number, since it is larger than the sum of its proper divisors (12911336834).

19890398902 is a wasteful number, since it uses less digits than its factorization.

19890398902 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18156 (or 18145 counting only the distinct ones).

The product of its (nonzero) digits is 2519424, while the sum is 58.

The spelling of 19890398902 in words is "nineteen billion, eight hundred ninety million, three hundred ninety-eight thousand, nine hundred two".