25246636778261 has 4 divisors (see below), whose sum is σ = 26117210460300. Its totient is φ = 24376063096224.

The previous prime is 25246636778227. The next prime is 25246636778273. The reversal of 25246636778261 is 16287763664252.

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 19295505802225 + 5951130976036 = 4392665^2 + 2439494^2 .

It is a cyclic number.

It is not a de Polignac number, because 25246636778261 - 2¹⁰ = 25246636777237 is a prime.

It is a super-2 number, since 2×25246636778261² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25246636778291) 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, 435286840976 + ... + 435286841033.

It is an arithmetic number, because the mean of its divisors is an integer number (6529302615075).

Almost surely, 2^{25246636778261} is an apocalyptic number.

It is an amenable number.

25246636778261 is a deficient number, since it is larger than the sum of its proper divisors (870573682039).

25246636778261 is an equidigital number, since it uses as much as digits as its factorization.

25246636778261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 870573682038.

The product of its digits is 243855360, while the sum is 65.

The spelling of 25246636778261 in words is "twenty-five trillion, two hundred forty-six billion, six hundred thirty-six million, seven hundred seventy-eight thousand, two hundred sixty-one".