20731020 has 24 divisors (see below), whose sum is σ = 58047024. Its totient is φ = 5528256.

The previous prime is 20731001. The next prime is 20731043. The reversal of 20731020 is 2013702.

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, 172699 + ... + 172818.

It is an arithmetic number, because the mean of its divisors is an integer number (2418626).

Almost surely, 2^20731020 is an apocalyptic number.

20731020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20731020 is an abundant number, since it is smaller than the sum of its proper divisors (37316004).

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

20731020 is a wasteful number, since it uses less digits than its factorization.

20731020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 345529 (or 345527 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 15.

The square root of 20731020 is about 4553.1329872957. The cubic root of 20731020 is about 274.7094230996.

Adding to 20731020 its reverse (2013702), we get a palindrome (22744722).

The spelling of 20731020 in words is "twenty million, seven hundred thirty-one thousand, twenty".