21066836 has 24 divisors (see below), whose sum is σ = 42731136. Its totient is φ = 8900640.

The previous prime is 21066833. The next prime is 21066841. The reversal of 21066836 is 63866012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21066833) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3311 + ... + 7286.

It is an arithmetic number, because the mean of its divisors is an integer number (1780464).

Almost surely, 2^21066836 is an apocalyptic number.

It is an amenable number.

21066836 is an abundant number, since it is smaller than the sum of its proper divisors (21664300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21066836 is a wasteful number, since it uses less digits than its factorization.

21066836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10679 (or 10677 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 21066836 is about 4589.8623073029. The cubic root of 21066836 is about 276.1847988735.

The spelling of 21066836 in words is "twenty-one million, sixty-six thousand, eight hundred thirty-six".