25940699809 has 4 divisors (see below), whose sum is σ = 25948181140. Its totient is φ = 25933218480.

The previous prime is 25940699783. The next prime is 25940699819. The reversal of 25940699809 is 90899604952.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 4616523025 + 21324176784 = 67945^2 + 146028^2 .

It is a cyclic number.

It is not a de Polignac number, because 25940699809 - 2²³ = 25932311201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25940699819) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3735462 + ... + 3742399.

It is an arithmetic number, because the mean of its divisors is an integer number (6487045285).

Almost surely, 2^25940699809 is an apocalyptic number.

It is an amenable number.

25940699809 is a deficient number, since it is larger than the sum of its proper divisors (7481331).

25940699809 is an equidigital number, since it uses as much as digits as its factorization.

25940699809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7481330.

The product of its (nonzero) digits is 12597120, while the sum is 61.

The spelling of 25940699809 in words is "twenty-five billion, nine hundred forty million, six hundred ninety-nine thousand, eight hundred nine".