25218138 has 32 divisors (see below), whose sum is σ = 55442880. Its totient is φ = 7583360.

The previous prime is 25218133. The next prime is 25218161. The reversal of 25218138 is 83181252.

It is not an unprimeable number, because it can be changed into a prime (25218133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7648 + ... + 10436.

It is an arithmetic number, because the mean of its divisors is an integer number (1732590).

Almost surely, 2^25218138 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25218138, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27721440).

25218138 is an abundant number, since it is smaller than the sum of its proper divisors (30224742).

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

25218138 is a wasteful number, since it uses less digits than its factorization.

25218138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2942.

The product of its digits is 3840, while the sum is 30.

The square root of 25218138 is about 5021.7664222861. The cubic root of 25218138 is about 293.2497647042.

It can be divided in two parts, 252 and 18138, that multiplied together give a triangular number (4570776 = T₃₀₂₃).

The spelling of 25218138 in words is "twenty-five million, two hundred eighteen thousand, one hundred thirty-eight".