19621889660 has 12 divisors (see below), whose sum is σ = 41205968328. Its totient is φ = 7848755856.

The previous prime is 19621889629. The next prime is 19621889669. The reversal of 19621889660 is 6698812691.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 19621889596 and 19621889605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19621889669) 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, 490547222 + ... + 490547261.

It is an arithmetic number, because the mean of its divisors is an integer number (3433830694).

Almost surely, 2^19621889660 is an apocalyptic number.

19621889660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19621889660 is an abundant number, since it is smaller than the sum of its proper divisors (21584078668).

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

19621889660 is a wasteful number, since it uses less digits than its factorization.

19621889660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 981094492 (or 981094490 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 56.

The spelling of 19621889660 in words is "nineteen billion, six hundred twenty-one million, eight hundred eighty-nine thousand, six hundred sixty".