25506801899 has 2 divisors, whose sum is σ = 25506801900. Its totient is φ = 25506801898.

The previous prime is 25506801871. The next prime is 25506801907. The reversal of 25506801899 is 99810860552.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 25506801899 - 2¹² = 25506797803 is a prime.

It is a super-2 number, since 2×25506801899² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 25506801899.

It is not a weakly prime, because it can be changed into another prime (25506801799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 12753400949 + 12753400950.

It is an arithmetic number, because the mean of its divisors is an integer number (12753400950).

Almost surely, 2^25506801899 is an apocalyptic number.

25506801899 is a deficient number, since it is larger than the sum of its proper divisors (1).

25506801899 is an equidigital number, since it uses as much as digits as its factorization.

25506801899 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1555200, while the sum is 53.

The spelling of 25506801899 in words is "twenty-five billion, five hundred six million, eight hundred one thousand, eight hundred ninety-nine".