21876091 has 4 divisors (see below), whose sum is σ = 21891312. Its totient is φ = 21860872.

The previous prime is 21876089. The next prime is 21876109. The reversal of 21876091 is 19067812.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21876091 - 2¹ = 21876089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21876791) 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, 5200 + ... + 8413.

It is an arithmetic number, because the mean of its divisors is an integer number (5472828).

Almost surely, 2^21876091 is an apocalyptic number.

21876091 is a deficient number, since it is larger than the sum of its proper divisors (15221).

21876091 is a wasteful number, since it uses less digits than its factorization.

21876091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15220.

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 21876091 is about 4677.1883648192. The cubic root of 21876091 is about 279.6768849274.

The spelling of 21876091 in words is "twenty-one million, eight hundred seventy-six thousand, ninety-one".