20731123 has 4 divisors (see below), whose sum is σ = 23692720. Its totient is φ = 17769528.

The previous prime is 20731121. The next prime is 20731127. The reversal of 20731123 is 32113702.

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

It is not a de Polignac number, because 20731123 - 2¹ = 20731121 is a prime.

It is a super-2 number, since 2×20731123² = 859558921682258, which contains 22 as substring.

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 20731123.

It is not an unprimeable number, because it can be changed into a prime (20731121) 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, 1480788 + ... + 1480801.

It is an arithmetic number, because the mean of its divisors is an integer number (5923180).

Almost surely, 2^20731123 is an apocalyptic number.

20731123 is a deficient number, since it is larger than the sum of its proper divisors (2961597).

20731123 is an equidigital number, since it uses as much as digits as its factorization.

20731123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2961596.

The product of its (nonzero) digits is 252, while the sum is 19.

The square root of 20731123 is about 4553.1442981746. The cubic root of 20731123 is about 274.7098780542.

Adding to 20731123 its reverse (32113702), we get a palindrome (52844825).

The spelling of 20731123 in words is "twenty million, seven hundred thirty-one thousand, one hundred twenty-three".