20712109 has 16 divisors (see below), whose sum is σ = 24022080. Its totient is φ = 17660160.

The previous prime is 20712091. The next prime is 20712113. The reversal of 20712109 is 90121702.

It is a cyclic number.

It is not a de Polignac number, because 20712109 - 2⁵ = 20712077 is a prime.

It is a super-3 number, since 3×20712109³ (a number of 23 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20712109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20712199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23179 + ... + 24055.

It is an arithmetic number, because the mean of its divisors is an integer number (1501380).

Almost surely, 2^20712109 is an apocalyptic number.

It is an amenable number.

20712109 is a deficient number, since it is larger than the sum of its proper divisors (3309971).

20712109 is a wasteful number, since it uses less digits than its factorization.

20712109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1020.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 20712109 is about 4551.0558115672. The cubic root of 20712109 is about 274.6258669865.

The spelling of 20712109 in words is "twenty million, seven hundred twelve thousand, one hundred nine".