21150419920 has 80 divisors (see below), whose sum is σ = 56228722560. Its totient is φ = 7247826432.

The previous prime is 21150419869. The next prime is 21150419921. The reversal of 21150419920 is 2991405112.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150419921) 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, 1211574 + ... + 1228906.

It is an arithmetic number, because the mean of its divisors is an integer number (702859032).

Almost surely, 2^21150419920 is an apocalyptic number.

21150419920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21150419920 is an abundant number, since it is smaller than the sum of its proper divisors (35078302640).

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

21150419920 is a wasteful number, since it uses less digits than its factorization.

21150419920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19532 (or 19526 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 34.

The spelling of 21150419920 in words is "twenty-one billion, one hundred fifty million, four hundred nineteen thousand, nine hundred twenty".