25781611 has 2 divisors, whose sum is σ = 25781612. Its totient is φ = 25781610.

The previous prime is 25781603. The next prime is 25781617. The reversal of 25781611 is 11618752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25781611 - 2³ = 25781603 is a prime.

It is not a weakly prime, because it can be changed into another prime (25781617) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12890805 + 12890806.

It is an arithmetic number, because the mean of its divisors is an integer number (12890806).

Almost surely, 2^25781611 is an apocalyptic number.

25781611 is a deficient number, since it is larger than the sum of its proper divisors (1).

25781611 is an equidigital number, since it uses as much as digits as its factorization.

25781611 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3360, while the sum is 31.

The square root of 25781611 is about 5077.5595515956. The cubic root of 25781611 is about 295.4178164592.

The spelling of 25781611 in words is "twenty-five million, seven hundred eighty-one thousand, six hundred eleven".