28426633308581 has 2 divisors, whose sum is σ = 28426633308582. Its totient is φ = 28426633308580.

The previous prime is 28426633308503. The next prime is 28426633308613. The reversal of 28426633308581 is 18580333662482.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 23524527343681 + 4902105964900 = 4850209^2 + 2214070^2 .

It is a cyclic number.

It is not a de Polignac number, because 28426633308581 - 2⁴² = 24028586797477 is a prime.

It is a super-2 number, since 2×28426633308581² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28426633308581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28426633338581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14213316654290 + 14213316654291.

It is an arithmetic number, because the mean of its divisors is an integer number (14213316654291).

Almost surely, 2^{28426633308581} is an apocalyptic number.

It is an amenable number.

28426633308581 is a deficient number, since it is larger than the sum of its proper divisors (1).

28426633308581 is an equidigital number, since it uses as much as digits as its factorization.

28426633308581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39813120, while the sum is 59.

The spelling of 28426633308581 in words is "twenty-eight trillion, four hundred twenty-six billion, six hundred thirty-three million, three hundred eight thousand, five hundred eighty-one".