20491284085 has 16 divisors (see below), whose sum is σ = 26020051200. Its totient is φ = 15459431680.

The previous prime is 20491284071. The next prime is 20491284089. The reversal of 20491284085 is 58048219402.

It is not a de Polignac number, because 20491284085 - 2¹⁹ = 20490759797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20491284089) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1246660 + ... + 1262989.

It is an arithmetic number, because the mean of its divisors is an integer number (1626253200).

Almost surely, 2^20491284085 is an apocalyptic number.

It is an amenable number.

20491284085 is a deficient number, since it is larger than the sum of its proper divisors (5528767115).

20491284085 is a wasteful number, since it uses less digits than its factorization.

20491284085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2509748.

The product of its (nonzero) digits is 184320, while the sum is 43.

The spelling of 20491284085 in words is "twenty billion, four hundred ninety-one million, two hundred eighty-four thousand, eighty-five".