20123709 has 16 divisors (see below), whose sum is σ = 27883200. Its totient is φ = 12894336.

The previous prime is 20123707. The next prime is 20123713. The reversal of 20123709 is 90732102.

It is not a de Polignac number, because 20123709 - 2¹ = 20123707 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26862 + ... + 27600.

It is an arithmetic number, because the mean of its divisors is an integer number (1742700).

Almost surely, 2^20123709 is an apocalyptic number.

20123709 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20123709 is a deficient number, since it is larger than the sum of its proper divisors (7759491).

20123709 is a wasteful number, since it uses less digits than its factorization.

20123709 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1084.

The product of its (nonzero) digits is 756, while the sum is 24.

The square root of 20123709 is about 4485.9457196894. The cubic root of 20123709 is about 272.0002748339. Note that the first 3 decimals are identical.

The spelling of 20123709 in words is "twenty million, one hundred twenty-three thousand, seven hundred nine".