25551521 has 2 divisors, whose sum is σ = 25551522. Its totient is φ = 25551520.

The previous prime is 25551517. The next prime is 25551541. The reversal of 25551521 is 12515552.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 25391521 + 160000 = 5039^2 + 400^2 .

It is a cyclic number.

It is not a de Polignac number, because 25551521 - 2² = 25551517 is a prime.

It is not a weakly prime, because it can be changed into another prime (25551541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12775760 + 12775761.

It is an arithmetic number, because the mean of its divisors is an integer number (12775761).

Almost surely, 2^25551521 is an apocalyptic number.

It is an amenable number.

25551521 is a deficient number, since it is larger than the sum of its proper divisors (1).

25551521 is an equidigital number, since it uses as much as digits as its factorization.

25551521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2500, while the sum is 26.

The square root of 25551521 is about 5054.8512342106. The cubic root of 25551521 is about 294.5363625792.

The spelling of 25551521 in words is "twenty-five million, five hundred fifty-one thousand, five hundred twenty-one".