25558261 has 2 divisors, whose sum is σ = 25558262. Its totient is φ = 25558260.

The previous prime is 25558241. The next prime is 25558277. The reversal of 25558261 is 16285552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21068100 + 4490161 = 4590^2 + 2119^2 .

It is a cyclic number.

It is not a de Polignac number, because 25558261 - 2¹¹ = 25556213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (25558201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12779130 + 12779131.

It is an arithmetic number, because the mean of its divisors is an integer number (12779131).

Almost surely, 2^25558261 is an apocalyptic number.

It is an amenable number.

25558261 is a deficient number, since it is larger than the sum of its proper divisors (1).

25558261 is an equidigital number, since it uses as much as digits as its factorization.

25558261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24000, while the sum is 34.

The square root of 25558261 is about 5055.5178765385. The cubic root of 25558261 is about 294.5622579791.

It can be divided in two parts, 2555 and 8261, that added together give a square (10816 = 104²).

The spelling of 25558261 in words is "twenty-five million, five hundred fifty-eight thousand, two hundred sixty-one".