25661250 has 60 divisors (see below), whose sum is σ = 69507438. Its totient is φ = 6840000.

The previous prime is 25661243. The next prime is 25661257. The reversal of 25661250 is 5216652.

It is an interprime number because it is at equal distance from previous prime (25661243) and next prime (25661257).

It can be written as a sum of positive squares in 5 ways, for example, as 651249 + 25010001 = 807^2 + 5001^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25661257) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 10110 + ... + 12390.

Almost surely, 2^25661250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25661250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34753719).

25661250 is an abundant number, since it is smaller than the sum of its proper divisors (43846188).

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

25661250 is a wasteful number, since it uses less digits than its factorization.

25661250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2309 (or 2291 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 25661250 is about 5065.6934372305. The cubic root of 25661250 is about 294.9573815671.

The spelling of 25661250 in words is "twenty-five million, six hundred sixty-one thousand, two hundred fifty".