25221042 has 96 divisors (see below), whose sum is σ = 70447104. Its totient is φ = 6328800.

The previous prime is 25221023. The next prime is 25221043. The reversal of 25221042 is 24012252.

It is a super-2 number, since 2×25221042² = 1272201919131528, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (25221043) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 42673 + ... + 43259.

It is an arithmetic number, because the mean of its divisors is an integer number (733824).

Almost surely, 2^25221042 is an apocalyptic number.

25221042 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 25221042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35223552).

25221042 is an abundant number, since it is smaller than the sum of its proper divisors (45226062).

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

25221042 is a wasteful number, since it uses less digits than its factorization.

25221042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644 (or 641 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 18.

The square root of 25221042 is about 5022.0555552483. The cubic root of 25221042 is about 293.2610206850.

Adding to 25221042 its reverse (24012252), we get a palindrome (49233294).

It can be divided in two parts, 252210 and 42, that added together give a palindrome (252252).

The spelling of 25221042 in words is "twenty-five million, two hundred twenty-one thousand, forty-two".