19865731044 has 12 divisors (see below), whose sum is σ = 46353372464. Its totient is φ = 6621910344.

The previous prime is 19865731043. The next prime is 19865731049. The reversal of 19865731044 is 44013756891.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 19865730984 and 19865731002.

It is not an unprimeable number, because it can be changed into a prime (19865731043) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 827738782 + ... + 827738805.

Almost surely, 2^19865731044 is an apocalyptic number.

It is an amenable number.

19865731044 is an abundant number, since it is smaller than the sum of its proper divisors (26487641420).

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

19865731044 is a wasteful number, since it uses less digits than its factorization.

19865731044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1655477594 (or 1655477592 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 48.

The spelling of 19865731044 in words is "nineteen billion, eight hundred sixty-five million, seven hundred thirty-one thousand, forty-four".