25402561 has 4 divisors (see below), whose sum is σ = 25434324. Its totient is φ = 25370800.

The previous prime is 25402541. The next prime is 25402571. The reversal of 25402561 is 16520452.

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 7075600 + 18326961 = 2660^2 + 4281^2 .

It is a cyclic number.

It is not a de Polignac number, because 25402561 - 2¹¹ = 25400513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (25402541) 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, 14650 + ... + 16291.

It is an arithmetic number, because the mean of its divisors is an integer number (6358581).

Almost surely, 2^25402561 is an apocalyptic number.

It is an amenable number.

25402561 is a deficient number, since it is larger than the sum of its proper divisors (31763).

25402561 is an equidigital number, since it uses as much as digits as its factorization.

25402561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31762.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 25402561 is about 5040.0953363999. The cubic root of 25402561 is about 293.9628850058.

The spelling of 25402561 in words is "twenty-five million, four hundred two thousand, five hundred sixty-one".