19890874644 has 48 divisors (see below), whose sum is σ = 48213760896. Its totient is φ = 6377459200.

The previous prime is 19890874643. The next prime is 19890874673. The reversal of 19890874644 is 44647809891.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19890874643) 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, 249777 + ... + 319640.

It is an arithmetic number, because the mean of its divisors is an integer number (1004453352).

Almost surely, 2^19890874644 is an apocalyptic number.

It is an amenable number.

19890874644 is an abundant number, since it is smaller than the sum of its proper divisors (28322886252).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

19890874644 is a wasteful number, since it uses less digits than its factorization.

19890874644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 569536 (or 569534 counting only the distinct ones).

The product of its (nonzero) digits is 13934592, while the sum is 60.

The spelling of 19890874644 in words is "nineteen billion, eight hundred ninety million, eight hundred seventy-four thousand, six hundred forty-four".