20708231 has 4 divisors (see below), whose sum is σ = 20723352. Its totient is φ = 20693112.

The previous prime is 20708221. The next prime is 20708249. The reversal of 20708231 is 13280702.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20708231 is a prime.

It is a super-2 number, since 2×20708231² = 857661662298722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20708197 and 20708206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20708201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5276 + ... + 8321.

It is an arithmetic number, because the mean of its divisors is an integer number (5180838).

Almost surely, 2^20708231 is an apocalyptic number.

20708231 is a deficient number, since it is larger than the sum of its proper divisors (15121).

20708231 is a wasteful number, since it uses less digits than its factorization.

20708231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15120.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 20708231 is about 4550.6297366409. The cubic root of 20708231 is about 274.6087261989.

Adding to 20708231 its reverse (13280702), we get a palindrome (33988933).

It can be divided in two parts, 2070 and 8231, that added together give a palindrome (10301).

The spelling of 20708231 in words is "twenty million, seven hundred eight thousand, two hundred thirty-one".