20494672591 has 2 divisors, whose sum is σ = 20494672592. Its totient is φ = 20494672590.

The previous prime is 20494672589. The next prime is 20494672607. The reversal of 20494672591 is 19527649402.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20494672591 - 2¹ = 20494672589 is a prime.

It is a super-2 number, since 2×20494672591² (a number of 21 digits) contains 22 as substring.

Together with 20494672589, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20494672691) 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, 10247336295 + 10247336296.

It is an arithmetic number, because the mean of its divisors is an integer number (10247336296).

Almost surely, 2^20494672591 is an apocalyptic number.

20494672591 is a deficient number, since it is larger than the sum of its proper divisors (1).

20494672591 is an equidigital number, since it uses as much as digits as its factorization.

20494672591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1088640, while the sum is 49.

The spelling of 20494672591 in words is "twenty billion, four hundred ninety-four million, six hundred seventy-two thousand, five hundred ninety-one".