21221542233405 has 48 divisors (see below), whose sum is σ = 36958232413440. Its totient is φ = 11264673619584.

The previous prime is 21221542233403. The next prime is 21221542233421. The reversal of 21221542233405 is 50433224512212.

21221542233405 is a `hidden beast` number, since 2 + 1 + 2 + 2 + 15 + 4 + 2 + 233 + 405 = 666.

It is not a de Polignac number, because 21221542233405 - 2¹ = 21221542233403 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221542233405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221542233401) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 6795622 + ... + 9414008.

It is an arithmetic number, because the mean of its divisors is an integer number (769963175280).

Almost surely, 2^{21221542233405} is an apocalyptic number.

It is an amenable number.

21221542233405 is a deficient number, since it is larger than the sum of its proper divisors (15736690180035).

21221542233405 is a wasteful number, since it uses less digits than its factorization.

21221542233405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2619250 (or 2619247 counting only the distinct ones).

The product of its (nonzero) digits is 115200, while the sum is 36.

Adding to 21221542233405 its reverse (50433224512212), we get a palindrome (71654766745617).

The spelling of 21221542233405 in words is "twenty-one trillion, two hundred twenty-one billion, five hundred forty-two million, two hundred thirty-three thousand, four hundred five".