20836864 has 20 divisors (see below), whose sum is σ = 41634054. Its totient is φ = 10418176.

The previous prime is 20836847. The next prime is 20836889. The reversal of 20836864 is 46863802.

It can be written as a sum of positive squares in only one way, i.e., 20793600 + 43264 = 4560^2 + 208^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19837 + ... + 20860.

Almost surely, 2^20836864 is an apocalyptic number.

It is an amenable number.

20836864 is a deficient number, since it is larger than the sum of its proper divisors (20797190).

20836864 is an frugal number, since it uses more digits than its factorization.

20836864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40715 (or 40699 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 37.

The square root of 20836864 is about 4564.7413946466. The cubic root of 20836864 is about 275.1761472025.

The spelling of 20836864 in words is "twenty million, eight hundred thirty-six thousand, eight hundred sixty-four".