25811790291 has 32 divisors (see below), whose sum is σ = 43709998080. Its totient is φ = 14747064768.

The previous prime is 25811790223. The next prime is 25811790313. The reversal of 25811790291 is 19209711852.

It is not a de Polignac number, because 25811790291 - 2¹⁵ = 25811757523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (25811790391) 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 in 31 ways as a sum of consecutive naturals, for example, 2060850 + ... + 2073336.

It is an arithmetic number, because the mean of its divisors is an integer number (1365937440).

Almost surely, 2^25811790291 is an apocalyptic number.

25811790291 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

25811790291 is a deficient number, since it is larger than the sum of its proper divisors (17898207789).

25811790291 is a wasteful number, since it uses less digits than its factorization.

25811790291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23440 (or 23434 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 45.

The spelling of 25811790291 in words is "twenty-five billion, eight hundred eleven million, seven hundred ninety thousand, two hundred ninety-one".