21191919180 has 48 divisors (see below), whose sum is σ = 59344324704. Its totient is φ = 5650516480.

The previous prime is 21191919169. The next prime is 21191919181. The reversal of 21191919180 is 8191919112.

It is not an unprimeable number, because it can be changed into a prime (21191919181) 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, 707794 + ... + 737126.

It is an arithmetic number, because the mean of its divisors is an integer number (1236340098).

Almost surely, 2^21191919180 is an apocalyptic number.

21191919180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21191919180 is an abundant number, since it is smaller than the sum of its proper divisors (38152405524).

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

21191919180 is a wasteful number, since it uses less digits than its factorization.

21191919180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41386 (or 41384 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 42.

The spelling of 21191919180 in words is "twenty-one billion, one hundred ninety-one million, nine hundred nineteen thousand, one hundred eighty".