21201091 has 8 divisors (see below), whose sum is σ = 22498560. Its totient is φ = 19909248.

The previous prime is 21201083. The next prime is 21201109. The reversal of 21201091 is 19010212.

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 21201091 - 2³ = 21201083 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21201031) 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, 8350 + ... + 10588.

It is an arithmetic number, because the mean of its divisors is an integer number (2812320).

Almost surely, 2^21201091 is an apocalyptic number.

21201091 is a deficient number, since it is larger than the sum of its proper divisors (1297469).

21201091 is a wasteful number, since it uses less digits than its factorization.

21201091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2813.

The product of its (nonzero) digits is 36, while the sum is 16.

The square root of 21201091 is about 4604.4642467935. The cubic root of 21201091 is about 276.7702483072.

The spelling of 21201091 in words is "twenty-one million, two hundred one thousand, ninety-one".