25531506 has 144 divisors (see below), whose sum is σ = 75366720. Its totient is φ = 6065280.

The previous prime is 25531453. The next prime is 25531523. The reversal of 25531506 is 60513552.

It is a self number, because there is not a number n which added to its sum of digits gives 25531506.

It is a congruent number.

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 71 ways as a sum of consecutive naturals, for example, 234180 + ... + 234288.

It is an arithmetic number, because the mean of its divisors is an integer number (523380).

Almost surely, 2^25531506 is an apocalyptic number.

25531506 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 25531506, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37683360).

25531506 is an abundant number, since it is smaller than the sum of its proper divisors (49835214).

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

25531506 is a wasteful number, since it uses less digits than its factorization.

25531506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161 (or 145 counting only the distinct ones).

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

The square root of 25531506 is about 5052.8710650481. The cubic root of 25531506 is about 294.4594371491.

The spelling of 25531506 in words is "twenty-five million, five hundred thirty-one thousand, five hundred six".