20855011 has 4 divisors (see below), whose sum is σ = 20961072. Its totient is φ = 20748952.

The previous prime is 20854991. The next prime is 20855017. The reversal of 20855011 is 11055802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11055802 = 2 ⋅5527901.

It is a cyclic number.

It is not a de Polignac number, because 20855011 - 2⁵ = 20854979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20855017) 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, 52735 + ... + 53128.

It is an arithmetic number, because the mean of its divisors is an integer number (5240268).

Almost surely, 2^20855011 is an apocalyptic number.

20855011 is a deficient number, since it is larger than the sum of its proper divisors (106061).

20855011 is a wasteful number, since it uses less digits than its factorization.

20855011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106060.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 20855011 is about 4566.7286978755. The cubic root of 20855011 is about 275.2560084296.

The spelling of 20855011 in words is "twenty million, eight hundred fifty-five thousand, eleven".