22156511521 has 2 divisors, whose sum is σ = 22156511522. Its totient is φ = 22156511520.

The previous prime is 22156511497. The next prime is 22156511537. The reversal of 22156511521 is 12511565122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21974801121 + 181710400 = 148239^2 + 13480^2 .

It is a cyclic number.

It is not a de Polignac number, because 22156511521 - 2¹³ = 22156503329 is a prime.

It is a super-2 number, since 2×22156511521² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (22156511551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11078255760 + 11078255761.

It is an arithmetic number, because the mean of its divisors is an integer number (11078255761).

Almost surely, 2^22156511521 is an apocalyptic number.

It is an amenable number.

22156511521 is a deficient number, since it is larger than the sum of its proper divisors (1).

22156511521 is an equidigital number, since it uses as much as digits as its factorization.

22156511521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6000, while the sum is 31.

The spelling of 22156511521 in words is "twenty-two billion, one hundred fifty-six million, five hundred eleven thousand, five hundred twenty-one".