21866136 has 16 divisors (see below), whose sum is σ = 54665400. Its totient is φ = 7288704.

The previous prime is 21866113. The next prime is 21866137. The reversal of 21866136 is 63166812.

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21866097 and 21866106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21866137) 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, 455521 + ... + 455568.

Almost surely, 2^21866136 is an apocalyptic number.

It is an amenable number.

21866136 is an abundant number, since it is smaller than the sum of its proper divisors (32799264).

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

21866136 is a wasteful number, since it uses less digits than its factorization.

21866136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 911098 (or 911094 counting only the distinct ones).

The product of its digits is 10368, while the sum is 33.

The square root of 21866136 is about 4676.1240359939. The cubic root of 21866136 is about 279.6344549548.

The spelling of 21866136 in words is "twenty-one million, eight hundred sixty-six thousand, one hundred thirty-six".