20723031 has 36 divisors (see below), whose sum is σ = 35176752. Its totient is φ = 11755296.

The previous prime is 20723029. The next prime is 20723041. The reversal of 20723031 is 13032702.

It is not a de Polignac number, because 20723031 - 2¹ = 20723029 is a prime.

It is a super-2 number, since 2×20723031² = 858888027653922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20722995 and 20723013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20723041) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 151195 + ... + 151331.

It is an arithmetic number, because the mean of its divisors is an integer number (977132).

Almost surely, 2^20723031 is an apocalyptic number.

20723031 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20723031 is a deficient number, since it is larger than the sum of its proper divisors (14453721).

20723031 is an frugal number, since it uses more digits than its factorization.

20723031 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 178 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 20723031 is about 4552.2555947574. The cubic root of 20723031 is about 274.6741308088.

Adding to 20723031 its reverse (13032702), we get a palindrome (33755733).

The spelling of 20723031 in words is "twenty million, seven hundred twenty-three thousand, thirty-one".