20907869 has 4 divisors (see below), whose sum is σ = 21628860. Its totient is φ = 20186880.

The previous prime is 20907863. The next prime is 20907877. The reversal of 20907869 is 96870902.

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

It can be written as a sum of positive squares in 2 ways, for example, as 9765625 + 11142244 = 3125^2 + 3338^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20907869 is a prime.

It is a super-2 number, since 2×20907869² = 874277972242322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20907863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 360452 + ... + 360509.

It is an arithmetic number, because the mean of its divisors is an integer number (5407215).

Almost surely, 2^20907869 is an apocalyptic number.

20907869 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20907869 is a deficient number, since it is larger than the sum of its proper divisors (720991).

20907869 is an equidigital number, since it uses as much as digits as its factorization.

20907869 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720990.

The product of its (nonzero) digits is 54432, while the sum is 41.

The square root of 20907869 is about 4572.5123291250. The cubic root of 20907869 is about 275.4883619753.

The spelling of 20907869 in words is "twenty million, nine hundred seven thousand, eight hundred sixty-nine".