23105515621 has 2 divisors, whose sum is σ = 23105515622. Its totient is φ = 23105515620.

The previous prime is 23105515613. The next prime is 23105515633. The reversal of 23105515621 is 12651550132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22624371396 + 481144225 = 150414^2 + 21935^2 .

It is a cyclic number.

It is not a de Polignac number, because 23105515621 - 2³ = 23105515613 is a prime.

It is a super-2 number, since 2×23105515621² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23105515691) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11552757810 + 11552757811.

It is an arithmetic number, because the mean of its divisors is an integer number (11552757811).

Almost surely, 2^23105515621 is an apocalyptic number.

It is an amenable number.

23105515621 is a deficient number, since it is larger than the sum of its proper divisors (1).

23105515621 is an equidigital number, since it uses as much as digits as its factorization.

23105515621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 31.

The spelling of 23105515621 in words is "twenty-three billion, one hundred five million, five hundred fifteen thousand, six hundred twenty-one".