21273385 has 16 divisors (see below), whose sum is σ = 30182400. Its totient is φ = 14083776.

The previous prime is 21273359. The next prime is 21273391. The reversal of 21273385 is 58337212.

It is not a de Polignac number, because 21273385 - 2⁷ = 21273257 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9465 + ... + 11494.

It is an arithmetic number, because the mean of its divisors is an integer number (1886400).

Almost surely, 2^21273385 is an apocalyptic number.

It is an amenable number.

21273385 is a deficient number, since it is larger than the sum of its proper divisors (8909015).

21273385 is a wasteful number, since it uses less digits than its factorization.

21273385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21000.

The product of its digits is 10080, while the sum is 31.

The square root of 21273385 is about 4612.3079905835. The cubic root of 21273385 is about 277.0844794395.

The spelling of 21273385 in words is "twenty-one million, two hundred seventy-three thousand, three hundred eighty-five".