25243661 has 4 divisors (see below), whose sum is σ = 25323612. Its totient is φ = 25163712.

The previous prime is 25243649. The next prime is 25243667. The reversal of 25243661 is 16634252.

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 4541161 + 20702500 = 2131^2 + 4550^2 .

It is a cyclic number.

It is not a de Polignac number, because 25243661 - 2⁶ = 25243597 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 (25243667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39500 + ... + 40133.

It is an arithmetic number, because the mean of its divisors is an integer number (6330903).

Almost surely, 2^25243661 is an apocalyptic number.

It is an amenable number.

25243661 is a deficient number, since it is larger than the sum of its proper divisors (79951).

25243661 is an equidigital number, since it uses as much as digits as its factorization.

25243661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79950.

The product of its digits is 8640, while the sum is 29.

The square root of 25243661 is about 5024.3070168930. The cubic root of 25243661 is about 293.3486629672.

The spelling of 25243661 in words is "twenty-five million, two hundred forty-three thousand, six hundred sixty-one".