25691013 has 20 divisors (see below), whose sum is σ = 39704940. Its totient is φ = 16535232.

The previous prime is 25691011. The next prime is 25691041. The reversal of 25691013 is 31019652.

It can be written as a sum of positive squares in 2 ways, for example, as 20088324 + 5602689 = 4482^2 + 2367^2 .

It is not a de Polignac number, because 25691013 - 2¹ = 25691011 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25691011) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3120 + ... + 7817.

It is an arithmetic number, because the mean of its divisors is an integer number (1985247).

Almost surely, 2^25691013 is an apocalyptic number.

It is an amenable number.

25691013 is a deficient number, since it is larger than the sum of its proper divisors (14013927).

25691013 is a wasteful number, since it uses less digits than its factorization.

25691013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10978 (or 10969 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 25691013 is about 5068.6302883521. The cubic root of 25691013 is about 295.0713721783.

The spelling of 25691013 in words is "twenty-five million, six hundred ninety-one thousand, thirteen".