21502523421411 has 16 divisors (see below), whose sum is σ = 28675017792000. Its totient is φ = 14332522598528.

The previous prime is 21502523421391. The next prime is 21502523421427. The reversal of 21502523421411 is 11412432520512.

It is a cyclic number.

It is not a de Polignac number, because 21502523421411 - 2²¹ = 21502521324259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21502523421811) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 543398635 + ... + 543438203.

It is an arithmetic number, because the mean of its divisors is an integer number (1792188612000).

Almost surely, 2^{21502523421411} is an apocalyptic number.

21502523421411 is a deficient number, since it is larger than the sum of its proper divisors (7172494370589).

21502523421411 is a wasteful number, since it uses less digits than its factorization.

21502523421411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66498.

The product of its (nonzero) digits is 19200, while the sum is 33.

Adding to 21502523421411 its reverse (11412432520512), we get a palindrome (32914955941923).

The spelling of 21502523421411 in words is "twenty-one trillion, five hundred two billion, five hundred twenty-three million, four hundred twenty-one thousand, four hundred eleven".