20431992840 has 128 divisors (see below), whose sum is σ = 70211957760. Its totient is φ = 4659542784.

The previous prime is 20431992829. The next prime is 20431992853. The reversal of 20431992840 is 4829913402.

It is a super-2 number, since 2×20431992840² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 20431992792 and 20431992801.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 344667 + ... + 399573.

It is an arithmetic number, because the mean of its divisors is an integer number (548530920).

Almost surely, 2^20431992840 is an apocalyptic number.

20431992840 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 20431992840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35105978880).

20431992840 is an abundant number, since it is smaller than the sum of its proper divisors (49779964920).

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

20431992840 is a wasteful number, since it uses less digits than its factorization.

20431992840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55371 (or 55367 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 42.

The spelling of 20431992840 in words is "twenty billion, four hundred thirty-one million, nine hundred ninety-two thousand, eight hundred forty".