20440806491 has 32 divisors (see below), whose sum is σ = 24710676480. Its totient is φ = 16529936544.

The previous prime is 20440806481. The next prime is 20440806497. The reversal of 20440806491 is 19460804402.

It is a cyclic number.

It is not a de Polignac number, because 20440806491 - 2¹⁸ = 20440544347 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20440806497) 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 in 31 ways as a sum of consecutive naturals, for example, 14204150 + ... + 14205588.

It is an arithmetic number, because the mean of its divisors is an integer number (772208640).

Almost surely, 2^20440806491 is an apocalyptic number.

20440806491 is a deficient number, since it is larger than the sum of its proper divisors (4269869989).

20440806491 is a wasteful number, since it uses less digits than its factorization.

20440806491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2615.

The product of its (nonzero) digits is 55296, while the sum is 38.

The spelling of 20440806491 in words is "twenty billion, four hundred forty million, eight hundred six thousand, four hundred ninety-one".