25644544993 has 2 divisors, whose sum is σ = 25644544994. Its totient is φ = 25644544992.

The previous prime is 25644544979. The next prime is 25644545021. The reversal of 25644544993 is 39944544652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20511109089 + 5133435904 = 143217^2 + 71648^2 .

It is a cyclic number.

It is not a de Polignac number, because 25644544993 - 2²¹ = 25642447841 is a prime.

It is not a weakly prime, because it can be changed into another prime (25644544973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12822272496 + 12822272497.

It is an arithmetic number, because the mean of its divisors is an integer number (12822272497).

Almost surely, 2^25644544993 is an apocalyptic number.

It is an amenable number.

25644544993 is a deficient number, since it is larger than the sum of its proper divisors (1).

25644544993 is an equidigital number, since it uses as much as digits as its factorization.

25644544993 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18662400, while the sum is 55.

The spelling of 25644544993 in words is "twenty-five billion, six hundred forty-four million, five hundred forty-four thousand, nine hundred ninety-three".