21091019202 has 96 divisors (see below), whose sum is σ = 51369012864. Its totient is φ = 6197817600.

The previous prime is 21091019197. The next prime is 21091019219. The reversal of 21091019202 is 20291019012.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2273758 + ... + 2283014.

It is an arithmetic number, because the mean of its divisors is an integer number (535093884).

Almost surely, 2^21091019202 is an apocalyptic number.

21091019202 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21091019202, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25684506432).

21091019202 is an abundant number, since it is smaller than the sum of its proper divisors (30277993662).

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

21091019202 is a wasteful number, since it uses less digits than its factorization.

21091019202 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9624 (or 9621 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The spelling of 21091019202 in words is "twenty-one billion, ninety-one million, nineteen thousand, two hundred two".