20731055 has 4 divisors (see below), whose sum is σ = 24877272. Its totient is φ = 16584840.

The previous prime is 20731049. The next prime is 20731057. The reversal of 20731055 is 55013702.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20731055 - 2⁶ = 20730991 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20731055.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731057) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2073101 + ... + 2073110.

It is an arithmetic number, because the mean of its divisors is an integer number (6219318).

Almost surely, 2^20731055 is an apocalyptic number.

20731055 is a deficient number, since it is larger than the sum of its proper divisors (4146217).

20731055 is an equidigital number, since it uses as much as digits as its factorization.

20731055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4146216.

The product of its (nonzero) digits is 1050, while the sum is 23.

The square root of 20731055 is about 4553.1368308014. The cubic root of 20731055 is about 274.7095776960.

Adding to 20731055 its reverse (55013702), we get a palindrome (75744757).

The spelling of 20731055 in words is "twenty million, seven hundred thirty-one thousand, fifty-five".