20836881 has 12 divisors (see below), whose sum is σ = 32413108. Its totient is φ = 12822624.

The previous prime is 20836847. The next prime is 20836889. The reversal of 20836881 is 18863802.

It can be written as a sum of positive squares in 2 ways, for example, as 14288400 + 6548481 = 3780^2 + 2559^2 .

It is not a de Polignac number, because 20836881 - 2⁶ = 20836817 is a prime.

It is a super-2 number, since 2×20836881² = 868351219616322, which contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20836889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88930 + ... + 89163.

Almost surely, 2^20836881 is an apocalyptic number.

It is an amenable number.

20836881 is a deficient number, since it is larger than the sum of its proper divisors (11576227).

20836881 is a wasteful number, since it uses less digits than its factorization.

20836881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178112 (or 178109 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 20836881 is about 4564.7432567451. The cubic root of 20836881 is about 275.1762220377.

The spelling of 20836881 in words is "twenty million, eight hundred thirty-six thousand, eight hundred eighty-one".