25551815129 has 2 divisors, whose sum is σ = 25551815130. Its totient is φ = 25551815128.

The previous prime is 25551815057. The next prime is 25551815141. The reversal of 25551815129 is 92151815552.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25527411529 + 24403600 = 159773^2 + 4940^2 .

It is a cyclic number.

It is not a de Polignac number, because 25551815129 - 2¹⁶ = 25551749593 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 25551815129.

It is not a weakly prime, because it can be changed into another prime (25551815329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12775907564 + 12775907565.

It is an arithmetic number, because the mean of its divisors is an integer number (12775907565).

Almost surely, 2^25551815129 is an apocalyptic number.

It is an amenable number.

25551815129 is a deficient number, since it is larger than the sum of its proper divisors (1).

25551815129 is an equidigital number, since it uses as much as digits as its factorization.

25551815129 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 180000, while the sum is 44.

The spelling of 25551815129 in words is "twenty-five billion, five hundred fifty-one million, eight hundred fifteen thousand, one hundred twenty-nine".