21146091 has 4 divisors (see below), whose sum is σ = 28194792. Its totient is φ = 14097392.

The previous prime is 21146057. The next prime is 21146101. The reversal of 21146091 is 19064112.

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 21146091 - 2¹⁰ = 21145067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21146891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3524346 + ... + 3524351.

It is an arithmetic number, because the mean of its divisors is an integer number (7048698).

Almost surely, 2^21146091 is an apocalyptic number.

21146091 is a deficient number, since it is larger than the sum of its proper divisors (7048701).

21146091 is an equidigital number, since it uses as much as digits as its factorization.

21146091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7048700.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 21146091 is about 4598.4879036483. The cubic root of 21146091 is about 276.5307080248.

The spelling of 21146091 in words is "twenty-one million, one hundred forty-six thousand, ninety-one".