21029190920 has 64 divisors (see below), whose sum is σ = 47542809600. Its totient is φ = 8371399680.

The previous prime is 21029190857. The next prime is 21029190929. The reversal of 21029190920 is 2909192012.

It is not an unprimeable number, because it can be changed into a prime (21029190929) 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, 9960665 + ... + 9962775.

It is an arithmetic number, because the mean of its divisors is an integer number (742856400).

Almost surely, 2^21029190920 is an apocalyptic number.

21029190920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21029190920 is an abundant number, since it is smaller than the sum of its proper divisors (26513618680).

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

21029190920 is a wasteful number, since it uses less digits than its factorization.

21029190920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3198 (or 3194 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 35.

The spelling of 21029190920 in words is "twenty-one billion, twenty-nine million, one hundred ninety thousand, nine hundred twenty".