25197681 has 12 divisors (see below), whose sum is σ = 33952592. Its totient is φ = 16621848.

The previous prime is 25197677. The next prime is 25197691. The reversal of 25197681 is 18679152.

It is not a de Polignac number, because 25197681 - 2² = 25197677 is a prime.

It is a super-2 number, since 2×25197681² = 1269846255555522, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (25197671) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 110890 + ... + 111116.

Almost surely, 2^25197681 is an apocalyptic number.

It is an amenable number.

25197681 is a deficient number, since it is larger than the sum of its proper divisors (8754911).

25197681 is an equidigital number, since it uses as much as digits as its factorization.

25197681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 620 (or 393 counting only the distinct ones).

The product of its digits is 30240, while the sum is 39.

The square root of 25197681 is about 5019.7291759616. The cubic root of 25197681 is about 293.1704483367.

It can be divided in two parts, 25197 and 681, that added together give a triangular number (25878 = T₂₂₇).

The spelling of 25197681 in words is "twenty-five million, one hundred ninety-seven thousand, six hundred eighty-one".