20831040 has 112 divisors (see below), whose sum is σ = 73517760. Its totient is φ = 5552640.

The previous prime is 20831017. The next prime is 20831051. The reversal of 20831040 is 4013802.

It is a happy number.

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7435 + ... + 9845.

Almost surely, 2^20831040 is an apocalyptic number.

20831040 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 20831040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36758880).

20831040 is an abundant number, since it is smaller than the sum of its proper divisors (52686720).

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

20831040 is a wasteful number, since it uses less digits than its factorization.

20831040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2437 (or 2421 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20831040 is about 4564.1034168827. The cubic root of 20831040 is about 275.1505071443.

Adding to 20831040 its reverse (4013802), we get a palindrome (24844842).

The spelling of 20831040 in words is "twenty million, eight hundred thirty-one thousand, forty".