21301508772 has 72 divisors (see below), whose sum is σ = 54606412224. Its totient is φ = 7000514496.

The previous prime is 21301508731. The next prime is 21301508773. The reversal of 21301508772 is 27780510312.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (21301508773) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1495878 + ... + 1510050.

It is an arithmetic number, because the mean of its divisors is an integer number (758422392).

Almost surely, 2^21301508772 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21301508772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27303206112).

21301508772 is an abundant number, since it is smaller than the sum of its proper divisors (33304903452).

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

21301508772 is a wasteful number, since it uses less digits than its factorization.

21301508772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14769 (or 14764 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The spelling of 21301508772 in words is "twenty-one billion, three hundred one million, five hundred eight thousand, seven hundred seventy-two".