25531235665 has 16 divisors (see below), whose sum is σ = 33798952656. Its totient is φ = 18393984000.

The previous prime is 25531235663. The next prime is 25531235671. The reversal of 25531235665 is 56653213552.

It can be written as a sum of positive squares in 8 ways, for example, as 5116827024 + 20414408641 = 71532^2 + 142879^2 .

It is not a de Polignac number, because 25531235665 - 2¹ = 25531235663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25531235663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4787436 + ... + 4792765.

It is an arithmetic number, because the mean of its divisors is an integer number (2112434541).

Almost surely, 2^25531235665 is an apocalyptic number.

It is an amenable number.

25531235665 is a deficient number, since it is larger than the sum of its proper divisors (8267716991).

25531235665 is a wasteful number, since it uses less digits than its factorization.

25531235665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9580260.

The product of its digits is 810000, while the sum is 43.

The spelling of 25531235665 in words is "twenty-five billion, five hundred thirty-one million, two hundred thirty-five thousand, six hundred sixty-five".