21091010304 has 288 divisors, whose sum is σ = 72095837184. Its totient is φ = 5320212480.

The previous prime is 21091010299. The next prime is 21091010329. The reversal of 21091010304 is 40301019012.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1600864 + ... + 1613984.

It is an arithmetic number, because the mean of its divisors is an integer number (250332768).

Almost surely, 2^21091010304 is an apocalyptic number.

21091010304 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21091010304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36047918592).

21091010304 is an abundant number, since it is smaller than the sum of its proper divisors (51004826880).

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

21091010304 is a wasteful number, since it uses less digits than its factorization.

21091010304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13183 (or 13169 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

Adding to 21091010304 its reverse (40301019012), we get a palindrome (61392029316).

The spelling of 21091010304 in words is "twenty-one billion, ninety-one million, ten thousand, three hundred four".