25561603 has 2 divisors, whose sum is σ = 25561604. Its totient is φ = 25561602.

The previous prime is 25561559. The next prime is 25561609. The reversal of 25561603 is 30616552.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25561603 is a prime.

It is not a weakly prime, because it can be changed into another prime (25561609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12780801 + 12780802.

It is an arithmetic number, because the mean of its divisors is an integer number (12780802).

Almost surely, 2^25561603 is an apocalyptic number.

25561603 is a deficient number, since it is larger than the sum of its proper divisors (1).

25561603 is an equidigital number, since it uses as much as digits as its factorization.

25561603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5400, while the sum is 28.

The square root of 25561603 is about 5055.8483956701. The cubic root of 25561603 is about 294.5750964133.

The spelling of 25561603 in words is "twenty-five million, five hundred sixty-one thousand, six hundred three".