25155661 has 2 divisors, whose sum is σ = 25155662. Its totient is φ = 25155660.

The previous prime is 25155659. The next prime is 25155667. The reversal of 25155661 is 16655152.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16564900 + 8590761 = 4070^2 + 2931^2 .

It is a cyclic number.

It is not a de Polignac number, because 25155661 - 2¹ = 25155659 is a prime.

Together with 25155659, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25155667) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12577830 + 12577831.

It is an arithmetic number, because the mean of its divisors is an integer number (12577831).

Almost surely, 2^25155661 is an apocalyptic number.

It is an amenable number.

25155661 is a deficient number, since it is larger than the sum of its proper divisors (1).

25155661 is an equidigital number, since it uses as much as digits as its factorization.

25155661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9000, while the sum is 31.

The square root of 25155661 is about 5015.5419447952. The cubic root of 25155661 is about 293.0073926389.

The spelling of 25155661 in words is "twenty-five million, one hundred fifty-five thousand, six hundred sixty-one".