21089867 has 8 divisors (see below), whose sum is σ = 22742160. Its totient is φ = 19491840.

The previous prime is 21089863. The next prime is 21089879. The reversal of 21089867 is 76898012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21089867 - 2² = 21089863 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (41).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21089863) 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, 12758 + ... + 14315.

It is an arithmetic number, because the mean of its divisors is an integer number (2842770).

Almost surely, 2^21089867 is an apocalyptic number.

21089867 is a deficient number, since it is larger than the sum of its proper divisors (1652293).

21089867 is a wasteful number, since it uses less digits than its factorization.

21089867 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27133.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 21089867 is about 4592.3705207659. The cubic root of 21089867 is about 276.2854071717.

The spelling of 21089867 in words is "twenty-one million, eighty-nine thousand, eight hundred sixty-seven".