25161557 has 4 divisors (see below), whose sum is σ = 25345356. Its totient is φ = 24977760.

The previous prime is 25161551. The next prime is 25161571. The reversal of 25161557 is 75516152.

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 18054001 + 7107556 = 4249^2 + 2666^2 .

It is a cyclic number.

It is not a de Polignac number, because 25161557 - 2⁴ = 25161541 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25161551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 91694 + ... + 91967.

It is an arithmetic number, because the mean of its divisors is an integer number (6336339).

Almost surely, 2^25161557 is an apocalyptic number.

It is an amenable number.

25161557 is a deficient number, since it is larger than the sum of its proper divisors (183799).

25161557 is a wasteful number, since it uses less digits than its factorization.

25161557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183798.

The product of its digits is 10500, while the sum is 32.

The square root of 25161557 is about 5016.1296833316. The cubic root of 25161557 is about 293.0302826043.

The spelling of 25161557 in words is "twenty-five million, one hundred sixty-one thousand, five hundred fifty-seven".