20825166491 has 2 divisors, whose sum is σ = 20825166492. Its totient is φ = 20825166490.

The previous prime is 20825166473. The next prime is 20825166497. The reversal of 20825166491 is 19466152802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20825166491 - 2²² = 20820972187 is a prime.

It is not a weakly prime, because it can be changed into another prime (20825166497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10412583245 + 10412583246.

It is an arithmetic number, because the mean of its divisors is an integer number (10412583246).

Almost surely, 2^20825166491 is an apocalyptic number.

20825166491 is a deficient number, since it is larger than the sum of its proper divisors (1).

20825166491 is an equidigital number, since it uses as much as digits as its factorization.

20825166491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 207360, while the sum is 44.

The spelling of 20825166491 in words is "twenty billion, eight hundred twenty-five million, one hundred sixty-six thousand, four hundred ninety-one".