25081640 has 16 divisors (see below), whose sum is σ = 56433780. Its totient is φ = 10032640.

The previous prime is 25081621. The next prime is 25081643. The reversal of 25081640 is 4618052.

It can be written as a sum of positive squares in 2 ways, for example, as 24186724 + 894916 = 4918^2 + 946^2 .

It is not an unprimeable number, because it can be changed into a prime (25081643) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 313481 + ... + 313560.

Almost surely, 2^25081640 is an apocalyptic number.

25081640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

25081640 is an abundant number, since it is smaller than the sum of its proper divisors (31352140).

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

25081640 is a wasteful number, since it uses less digits than its factorization.

25081640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 627052 (or 627048 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 25081640 is about 5008.1573457710. The cubic root of 25081640 is about 292.7197170578.

Adding to 25081640 its reverse (4618052), we get a palindrome (29699692).

The spelling of 25081640 in words is "twenty-five million, eighty-one thousand, six hundred forty".