20216806 has 4 divisors (see below), whose sum is σ = 30325212. Its totient is φ = 10108402.

The previous prime is 20216761. The next prime is 20216827. The reversal of 20216806 is 60861202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 60861202 = 2 ⋅30430601.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5054200 + ... + 5054203.

It is an arithmetic number, because the mean of its divisors is an integer number (7581303).

Almost surely, 2^20216806 is an apocalyptic number.

20216806 is a deficient number, since it is larger than the sum of its proper divisors (10108406).

20216806 is a wasteful number, since it uses less digits than its factorization.

20216806 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10108405.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 20216806 is about 4496.3102650951. The cubic root of 20216806 is about 272.4190753725.

The spelling of 20216806 in words is "twenty million, two hundred sixteen thousand, eight hundred six".