20946815 has 4 divisors (see below), whose sum is σ = 25136184. Its totient is φ = 16757448.

The previous prime is 20946803. The next prime is 20946817. The reversal of 20946815 is 51864902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 51864902 = 2 ⋅25932451.

It is a cyclic number.

It is not a de Polignac number, because 20946815 - 2⁴ = 20946799 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20946817) 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, 2094677 + ... + 2094686.

It is an arithmetic number, because the mean of its divisors is an integer number (6284046).

Almost surely, 2^20946815 is an apocalyptic number.

20946815 is a deficient number, since it is larger than the sum of its proper divisors (4189369).

20946815 is an equidigital number, since it uses as much as digits as its factorization.

20946815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4189368.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 20946815 is about 4576.7690568784. The cubic root of 20946815 is about 275.6593106061.

The spelling of 20946815 in words is "twenty million, nine hundred forty-six thousand, eight hundred fifteen".