25540242 has 64 divisors (see below), whose sum is σ = 65076480. Its totient is φ = 6499584.

The previous prime is 25540217. The next prime is 25540243. The reversal of 25540242 is 24204552.

It is a happy number.

It is a super-2 number, since 2×25540242² = 1304607922837128, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (25540243) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 15028 + ... + 16640.

It is an arithmetic number, because the mean of its divisors is an integer number (1016820).

Almost surely, 2^25540242 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25540242, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32538240).

25540242 is an abundant number, since it is smaller than the sum of its proper divisors (39536238).

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

25540242 is a wasteful number, since it uses less digits than its factorization.

25540242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1667.

The product of its (nonzero) digits is 3200, while the sum is 24.

The square root of 25540242 is about 5053.7354501398. The cubic root of 25540242 is about 294.4930179375.

Adding to 25540242 its reverse (24204552), we get a palindrome (49744794).

The spelling of 25540242 in words is "twenty-five million, five hundred forty thousand, two hundred forty-two".