25715561 has 4 divisors (see below), whose sum is σ = 26077824. Its totient is φ = 25353300.

The previous prime is 25715549. The next prime is 25715567. The reversal of 25715561 is 16551752.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 25715561 - 2¹⁰ = 25714537 is a prime.

It is a super-2 number, since 2×25715561² = 1322580155089442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25715567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 181025 + ... + 181166.

It is an arithmetic number, because the mean of its divisors is an integer number (6519456).

Almost surely, 2^25715561 is an apocalyptic number.

It is an amenable number.

25715561 is a deficient number, since it is larger than the sum of its proper divisors (362263).

25715561 is an equidigital number, since it uses as much as digits as its factorization.

25715561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362262.

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

The square root of 25715561 is about 5071.0512716793. The cubic root of 25715561 is about 295.1653234006.

The spelling of 25715561 in words is "twenty-five million, seven hundred fifteen thousand, five hundred sixty-one".