21201222021984 has 72 divisors (see below), whose sum is σ = 60293228846760. Its totient is φ = 7066809835008.

The previous prime is 21201222021979. The next prime is 21201222022051. The reversal of 21201222021984 is 48912022210212.

It is a happy number.

21201222021984 is a `hidden beast` number, since 212 + 0 + 1 + 2 + 220 + 219 + 8 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6418507 + ... + 9143285.

It is an arithmetic number, because the mean of its divisors is an integer number (837405956205).

Almost surely, 2^{21201222021984} is an apocalyptic number.

21201222021984 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21201222021984 is an abundant number, since it is smaller than the sum of its proper divisors (39092006824776).

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

21201222021984 is a wasteful number, since it uses less digits than its factorization.

21201222021984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2751812 (or 2751801 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 21201222021984 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, twenty-one thousand, nine hundred eighty-four".