20431040 has 84 divisors (see below), whose sum is σ = 56637936. Its totient is φ = 6999552.

The previous prime is 20431039. The next prime is 20431043. The reversal of 20431040 is 4013402.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is not an unprimeable number, because it can be changed into a prime (20431043) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15029 + ... + 16331.

Almost surely, 2^20431040 is an apocalyptic number.

20431040 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 20431040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28318968).

20431040 is an abundant number, since it is smaller than the sum of its proper divisors (36206896).

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

20431040 is a wasteful number, since it uses less digits than its factorization.

20431040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1334 (or 1317 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 20431040 is about 4520.0707959057. The cubic root of 20431040 is about 273.3779555677.

Adding to 20431040 its reverse (4013402), we get a palindrome (24444442).

The spelling of 20431040 in words is "twenty million, four hundred thirty-one thousand, forty".