221905890432 has 72 divisors (see below), whose sum is σ = 638603327115. Its totient is φ = 73963300608.

The previous prime is 221905890331. The next prime is 221905890469. The reversal of 221905890432 is 234098509122.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

221905890432 is a `hidden beast` number, since 2 + 21 + 9 + 0 + 589 + 0 + 43 + 2 = 666.

It can be written as a sum of positive squares in only one way, i.e., 110952945216 + 110952945216 = 333096^2 + 333096^2 .

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

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=333096.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 15981669 + ... + 15995547.

Almost surely, 2^221905890432 is an apocalyptic number.

It is an amenable number.

221905890432 is an abundant number, since it is smaller than the sum of its proper divisors (416697436683).

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

221905890432 is an frugal number, since it uses more digits than its factorization.

221905890432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27778 (or 13884 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 221905890432 in words is "two hundred twenty-one billion, nine hundred five million, eight hundred ninety thousand, four hundred thirty-two".