25561530 has 48 divisors (see below), whose sum is σ = 66852864. Its totient is φ = 6776160.

The previous prime is 25561519. The next prime is 25561541. The reversal of 25561530 is 3516552.

It is an interprime number because it is at equal distance from previous prime (25561519) and next prime (25561541).

It is a junction number, because it is equal to n+sod(n) for n = 25561494 and 25561503.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16447 + ... + 17933.

It is an arithmetic number, because the mean of its divisors is an integer number (1392768).

Almost surely, 2^25561530 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 25561530, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33426432).

25561530 is an abundant number, since it is smaller than the sum of its proper divisors (41291334).

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

25561530 is a wasteful number, since it uses less digits than its factorization.

25561530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1691 (or 1688 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 25561530 is about 5055.8411763029. The cubic root of 25561530 is about 294.5748159927.

The spelling of 25561530 in words is "twenty-five million, five hundred sixty-one thousand, five hundred thirty".