26638457497 has 2 divisors, whose sum is σ = 26638457498. Its totient is φ = 26638457496.

The previous prime is 26638457453. The next prime is 26638457537. The reversal of 26638457497 is 79475483662.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18037564416 + 8600893081 = 134304^2 + 92741^2 .

It is a cyclic number.

It is not a de Polignac number, because 26638457497 - 2⁷ = 26638457369 is a prime.

It is not a weakly prime, because it can be changed into another prime (26638457597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 13319228748 + 13319228749.

It is an arithmetic number, because the mean of its divisors is an integer number (13319228749).

Almost surely, 2^26638457497 is an apocalyptic number.

It is an amenable number.

26638457497 is a deficient number, since it is larger than the sum of its proper divisors (1).

26638457497 is an equidigital number, since it uses as much as digits as its factorization.

26638457497 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60963840, while the sum is 61.

The spelling of 26638457497 in words is "twenty-six billion, six hundred thirty-eight million, four hundred fifty-seven thousand, four hundred ninety-seven".