21054091 has 8 divisors (see below), whose sum is σ = 21818160. Its totient is φ = 20303712.

The previous prime is 21054067. The next prime is 21054119. The reversal of 21054091 is 19045012.

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 21054091 - 2¹¹ = 21052043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21054791) 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, 240 + ... + 6493.

It is an arithmetic number, because the mean of its divisors is an integer number (2727270).

Almost surely, 2^21054091 is an apocalyptic number.

21054091 is a deficient number, since it is larger than the sum of its proper divisors (764069).

21054091 is an equidigital number, since it uses as much as digits as its factorization.

21054091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6845.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 21054091 is about 4588.4737113772. The cubic root of 21054091 is about 276.1290922748.

The spelling of 21054091 in words is "twenty-one million, fifty-four thousand, ninety-one".