25661240 has 32 divisors (see below), whose sum is σ = 62987760. Its totient is φ = 9331200.

The previous prime is 25661231. The next prime is 25661243. The reversal of 25661240 is 4216652.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (25661243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28721 + ... + 29600.

Almost surely, 2^25661240 is an apocalyptic number.

25661240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25661240 is an abundant number, since it is smaller than the sum of its proper divisors (37326520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

25661240 is a wasteful number, since it uses less digits than its factorization.

25661240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58343 (or 58339 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 25661240 is about 5065.6924501987. The cubic root of 25661240 is about 294.9573432528.

Adding to 25661240 its reverse (4216652), we get a palindrome (29877892).

It can be divided in two parts, 256612 and 40, that added together give a palindrome (256652).

The spelling of 25661240 in words is "twenty-five million, six hundred sixty-one thousand, two hundred forty".