25563521 has 2 divisors, whose sum is σ = 25563522. Its totient is φ = 25563520.

The previous prime is 25563509. The next prime is 25563553. The reversal of 25563521 is 12536552.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19492225 + 6071296 = 4415^2 + 2464^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-25563521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (25563581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12781760 + 12781761.

It is an arithmetic number, because the mean of its divisors is an integer number (12781761).

Almost surely, 2^25563521 is an apocalyptic number.

It is an amenable number.

25563521 is a deficient number, since it is larger than the sum of its proper divisors (1).

25563521 is an equidigital number, since it uses as much as digits as its factorization.

25563521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9000, while the sum is 29.

The square root of 25563521 is about 5056.0380734326. The cubic root of 25563521 is about 294.5824639860.

The spelling of 25563521 in words is "twenty-five million, five hundred sixty-three thousand, five hundred twenty-one".