21235771072 has 56 divisors (see below), whose sum is σ = 43649798400. Its totient is φ = 10238355456.

The previous prime is 21235771061. The next prime is 21235771087. The reversal of 21235771072 is 27017753212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1494433 + ... + 1508575.

Almost surely, 2^21235771072 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 21235771072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21824899200).

21235771072 is an abundant number, since it is smaller than the sum of its proper divisors (22414027328).

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

21235771072 is a wasteful number, since it uses less digits than its factorization.

21235771072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14993 (or 14983 counting only the distinct ones).

The product of its (nonzero) digits is 41160, while the sum is 37.

The spelling of 21235771072 in words is "twenty-one billion, two hundred thirty-five million, seven hundred seventy-one thousand, seventy-two".