20390706 has 24 divisors (see below), whose sum is σ = 50491584. Its totient is φ = 5825880.

The previous prime is 20390681. The next prime is 20390707. The reversal of 20390706 is 60709302.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20390706.

It is not an unprimeable number, because it can be changed into a prime (20390707) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 80790 + ... + 81041.

It is an arithmetic number, because the mean of its divisors is an integer number (2103816).

Almost surely, 2^20390706 is an apocalyptic number.

20390706 is an abundant number, since it is smaller than the sum of its proper divisors (30100878).

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

20390706 is a wasteful number, since it uses less digits than its factorization.

20390706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161846 (or 161843 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 20390706 is about 4515.6069359500. The cubic root of 20390706 is about 273.1979404147.

It can be divided in two parts, 203 and 90706, that added together give a palindrome (90909).

The spelling of 20390706 in words is "twenty million, three hundred ninety thousand, seven hundred six".