20431140 has 24 divisors (see below), whose sum is σ = 57207360. Its totient is φ = 5448288.

The previous prime is 20431123. The next prime is 20431171. The reversal of 20431140 is 4113402.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 170200 + ... + 170319.

It is an arithmetic number, because the mean of its divisors is an integer number (2383640).

Almost surely, 2^20431140 is an apocalyptic number.

20431140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20431140 is an abundant number, since it is smaller than the sum of its proper divisors (36776220).

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

20431140 is a wasteful number, since it uses less digits than its factorization.

20431140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 340531 (or 340529 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 20431140 is about 4520.0818576659. The cubic root of 20431140 is about 273.3784015844.

Adding to 20431140 its reverse (4113402), we get a palindrome (24544542).

The spelling of 20431140 in words is "twenty million, four hundred thirty-one thousand, one hundred forty".