21469091 has 4 divisors (see below), whose sum is σ = 24536112. Its totient is φ = 18402072.

The previous prime is 21469073. The next prime is 21469121. The reversal of 21469091 is 19096412.

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 21469091 - 2⁶ = 21469027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21469001) 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, 1533500 + ... + 1533513.

It is an arithmetic number, because the mean of its divisors is an integer number (6134028).

Almost surely, 2^21469091 is an apocalyptic number.

21469091 is a deficient number, since it is larger than the sum of its proper divisors (3067021).

21469091 is an equidigital number, since it uses as much as digits as its factorization.

21469091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3067020.

The product of its (nonzero) digits is 3888, while the sum is 32.

The square root of 21469091 is about 4633.4750457945. The cubic root of 21469091 is about 277.9315731386.

The spelling of 21469091 in words is "twenty-one million, four hundred sixty-nine thousand, ninety-one".