20838815 has 4 divisors (see below), whose sum is σ = 25006584. Its totient is φ = 16671048.

The previous prime is 20838803. The next prime is 20838823. The reversal of 20838815 is 51883802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51883802 = 2 ⋅25941901.

It is a cyclic number.

It is not a de Polignac number, because 20838815 - 2⁶ = 20838751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2083877 + ... + 2083886.

It is an arithmetic number, because the mean of its divisors is an integer number (6251646).

Almost surely, 2^20838815 is an apocalyptic number.

20838815 is a deficient number, since it is larger than the sum of its proper divisors (4167769).

20838815 is an equidigital number, since it uses as much as digits as its factorization.

20838815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4167768.

The product of its (nonzero) digits is 15360, while the sum is 35.

The square root of 20838815 is about 4564.9550928788. The cubic root of 20838815 is about 275.1847353776.

The spelling of 20838815 in words is "twenty million, eight hundred thirty-eight thousand, eight hundred fifteen".