20431423440 has 120 divisors (see below), whose sum is σ = 69070305408. Its totient is φ = 5412268800.

The previous prime is 20431423423. The next prime is 20431423471. The reversal of 20431423440 is 4432413402.

It is a happy number.

20431423440 is a `hidden beast` number, since 2 + 0 + 4 + 314 + 2 + 344 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14757 + ... + 202683.

Almost surely, 2^20431423440 is an apocalyptic number.

20431423440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20431423440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34535152704).

20431423440 is an abundant number, since it is smaller than the sum of its proper divisors (48638881968).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20431423440 is a wasteful number, since it uses less digits than its factorization.

20431423440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188097 (or 188088 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

Adding to 20431423440 its reverse (4432413402), we get a palindrome (24863836842).

The spelling of 20431423440 in words is "twenty billion, four hundred thirty-one million, four hundred twenty-three thousand, four hundred forty".