25039681 has 2 divisors, whose sum is σ = 25039682. Its totient is φ = 25039680.

The previous prime is 25039669. The next prime is 25039697. The reversal of 25039681 is 18693052.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24910081 + 129600 = 4991^2 + 360^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25039681 is a prime.

It is a super-4 number, since 4×25039681⁴ (a number of 31 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3, 2.

It is not a weakly prime, because it can be changed into another prime (25039601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12519840 + 12519841.

It is an arithmetic number, because the mean of its divisors is an integer number (12519841).

Almost surely, 2^25039681 is an apocalyptic number.

It is an amenable number.

25039681 is a deficient number, since it is larger than the sum of its proper divisors (1).

25039681 is an equidigital number, since it uses as much as digits as its factorization.

25039681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 25039681 is about 5003.9665266666. The cubic root of 25039681 is about 292.5563959731.

The spelling of 25039681 in words is "twenty-five million, thirty-nine thousand, six hundred eighty-one".