21386211 has 16 divisors (see below), whose sum is σ = 35551488. Its totient is φ = 11109600.

The previous prime is 21386203. The next prime is 21386219. The reversal of 21386211 is 11268312.

It is an interprime number because it is at equal distance from previous prime (21386203) and next prime (21386219).

It is not a de Polignac number, because 21386211 - 2³ = 21386203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21386219) 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 15 ways as a sum of consecutive naturals, for example, 46060 + ... + 46521.

It is an arithmetic number, because the mean of its divisors is an integer number (2221968).

Almost surely, 2^21386211 is an apocalyptic number.

21386211 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21386211 is a deficient number, since it is larger than the sum of its proper divisors (14165277).

21386211 is a wasteful number, since it uses less digits than its factorization.

21386211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92602.

The product of its digits is 576, while the sum is 24.

The square root of 21386211 is about 4624.5227861910. The cubic root of 21386211 is about 277.5734664668.

The spelling of 21386211 in words is "twenty-one million, three hundred eighty-six thousand, two hundred eleven".