21522123245551 has 16 divisors (see below), whose sum is σ = 22484935968768. Its totient is φ = 20561577141600.

The previous prime is 21522123245533. The next prime is 21522123245617. The reversal of 21522123245551 is 15554232122512.

It is a cyclic number.

It is not a de Polignac number, because 21522123245551 - 2¹³ = 21522123237359 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21522123248551) 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, 88130146 + ... + 88374016.

It is an arithmetic number, because the mean of its divisors is an integer number (1405308498048).

Almost surely, 2^{21522123245551} is an apocalyptic number.

21522123245551 is a deficient number, since it is larger than the sum of its proper divisors (962812723217).

21522123245551 is a wasteful number, since it uses less digits than its factorization.

21522123245551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248502.

The product of its digits is 240000, while the sum is 40.

The spelling of 21522123245551 in words is "twenty-one trillion, five hundred twenty-two billion, one hundred twenty-three million, two hundred forty-five thousand, five hundred fifty-one".