21000814722 has 72 divisors (see below), whose sum is σ = 48370205520. Its totient is φ = 6583842000.

The previous prime is 21000814691. The next prime is 21000814739. The reversal of 21000814722 is 22741800012.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 891597 + ... + 914847.

It is an arithmetic number, because the mean of its divisors is an integer number (671808410).

Almost surely, 2^21000814722 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000814722, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24185102760).

21000814722 is an abundant number, since it is smaller than the sum of its proper divisors (27369390798).

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

21000814722 is a wasteful number, since it uses less digits than its factorization.

21000814722 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23436 (or 23414 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The spelling of 21000814722 in words is "twenty-one billion, eight hundred fourteen thousand, seven hundred twenty-two".