19891812102 has 16 divisors (see below), whose sum is σ = 40155435072. Its totient is φ = 6568635560.

The previous prime is 19891812089. The next prime is 19891812103. The reversal of 19891812102 is 20121819891.

It is a happy number.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19891812103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15491424 + ... + 15492707.

It is an arithmetic number, because the mean of its divisors is an integer number (2509714692).

Almost surely, 2^19891812102 is an apocalyptic number.

19891812102 is an abundant number, since it is smaller than the sum of its proper divisors (20263622970).

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

19891812102 is a wasteful number, since it uses less digits than its factorization.

19891812102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30984243.

The product of its (nonzero) digits is 20736, while the sum is 42.

The spelling of 19891812102 in words is "nineteen billion, eight hundred ninety-one million, eight hundred twelve thousand, one hundred two".