21220923996 has 60 divisors (see below), whose sum is σ = 55633141872. Its totient is φ = 7053564672.

The previous prime is 21220923979. The next prime is 21220924027. The reversal of 21220923996 is 69932902212.

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 21601 + ... + 207143.

Almost surely, 2^21220923996 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 21220923996, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27816570936).

21220923996 is an abundant number, since it is smaller than the sum of its proper divisors (34412217876).

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

21220923996 is a wasteful number, since it uses less digits than its factorization.

21220923996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185912 (or 185901 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The spelling of 21220923996 in words is "twenty-one billion, two hundred twenty million, nine hundred twenty-three thousand, nine hundred ninety-six".