20431091989 has 48 divisors (see below), whose sum is σ = 27677376000. Its totient is φ = 14869461600.

The previous prime is 20431091987. The next prime is 20431092061. The reversal of 20431091989 is 98919013402.

It is a happy number.

It is not a de Polignac number, because 20431091989 - 2¹ = 20431091987 is a prime.

It is a super-2 number, since 2×20431091989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20431091987) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 713062 + ... + 741160.

It is an arithmetic number, because the mean of its divisors is an integer number (576612000).

Almost surely, 2^20431091989 is an apocalyptic number.

It is an amenable number.

20431091989 is a deficient number, since it is larger than the sum of its proper divisors (7246284011).

20431091989 is a wasteful number, since it uses less digits than its factorization.

20431091989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28214 (or 28207 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 46.

The spelling of 20431091989 in words is "twenty billion, four hundred thirty-one million, ninety-one thousand, nine hundred eighty-nine".