21222235205556 has 96 divisors (see below), whose sum is σ = 61752118686720. Its totient is φ = 5510955744000.

The previous prime is 21222235205539. The next prime is 21222235205557. The reversal of 21222235205556 is 65550253222212.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222235205557) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1148115 + ... + 6615333.

It is an arithmetic number, because the mean of its divisors is an integer number (643251236320).

Almost surely, 2^{21222235205556} is an apocalyptic number.

It is an amenable number.

21222235205556 is an abundant number, since it is smaller than the sum of its proper divisors (40529883481164).

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

21222235205556 is a wasteful number, since it uses less digits than its factorization.

21222235205556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5471445 (or 5471443 counting only the distinct ones).

The product of its (nonzero) digits is 720000, while the sum is 42.

Adding to 21222235205556 its reverse (65550253222212), we get a palindrome (86772488427768).

The spelling of 21222235205556 in words is "twenty-one trillion, two hundred twenty-two billion, two hundred thirty-five million, two hundred five thousand, five hundred fifty-six".