25901665 has 8 divisors (see below), whose sum is σ = 31922280. Its totient is φ = 20161152.

The previous prime is 25901663. The next prime is 25901671. The reversal of 25901665 is 56610952.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7273809 + 18627856 = 2697^2 + 4316^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 25901665 - 2¹ = 25901663 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25901665.

It is not an unprimeable number, because it can be changed into a prime (25901663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69820 + ... + 70189.

It is an arithmetic number, because the mean of its divisors is an integer number (3990285).

Almost surely, 2^25901665 is an apocalyptic number.

It is an amenable number.

25901665 is a deficient number, since it is larger than the sum of its proper divisors (6020615).

25901665 is a wasteful number, since it uses less digits than its factorization.

25901665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140051.

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 25901665 is about 5089.3678389364. The cubic root of 25901665 is about 295.8756515979.

It can be divided in two parts, 259016 and 65, that added together give a square (259081 = 509²).

The spelling of 25901665 in words is "twenty-five million, nine hundred one thousand, six hundred sixty-five".