21049222656 has 960 divisors, whose sum is σ = 80821255680. Its totient is φ = 4706795520.

The previous prime is 21049222619. The next prime is 21049222679. The reversal of 21049222656 is 65622294012.

It is a congruent number.

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 95 ways as a sum of consecutive naturals, for example, 725835250 + ... + 725835278.

It is an arithmetic number, because the mean of its divisors is an integer number (84188808).

Almost surely, 2^21049222656 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 21049222656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40410627840).

21049222656 is an abundant number, since it is smaller than the sum of its proper divisors (59772033024).

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

21049222656 is a wasteful number, since it uses less digits than its factorization.

21049222656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 39.

The spelling of 21049222656 in words is "twenty-one billion, forty-nine million, two hundred twenty-two thousand, six hundred fifty-six".