21626133281 has 2 divisors, whose sum is σ = 21626133282. Its totient is φ = 21626133280.

The previous prime is 21626133251. The next prime is 21626133329. The reversal of 21626133281 is 18233162612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20017722256 + 1608411025 = 141484^2 + 40105^2 .

It is a cyclic number.

It is not a de Polignac number, because 21626133281 - 2²² = 21621938977 is a prime.

It is a super-2 number, since 2×21626133281² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21626133251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10813066640 + 10813066641.

It is an arithmetic number, because the mean of its divisors is an integer number (10813066641).

Almost surely, 2^21626133281 is an apocalyptic number.

It is an amenable number.

21626133281 is a deficient number, since it is larger than the sum of its proper divisors (1).

21626133281 is an equidigital number, since it uses as much as digits as its factorization.

21626133281 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 35.

Adding to 21626133281 its reverse (18233162612), we get a palindrome (39859295893).

The spelling of 21626133281 in words is "twenty-one billion, six hundred twenty-six million, one hundred thirty-three thousand, two hundred eighty-one".