21166419 has 16 divisors (see below), whose sum is σ = 28708992. Its totient is φ = 13869888.

The previous prime is 21166381. The next prime is 21166441. The reversal of 21166419 is 91466112.

It is a happy number.

It is not a de Polignac number, because 21166419 - 2⁸ = 21166163 is a prime.

It is a super-2 number, since 2×21166419² = 896034586567122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21166489) 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, 74652 + ... + 74934.

It is an arithmetic number, because the mean of its divisors is an integer number (1794312).

Almost surely, 2^21166419 is an apocalyptic number.

21166419 is a deficient number, since it is larger than the sum of its proper divisors (7542573).

21166419 is a wasteful number, since it uses less digits than its factorization.

21166419 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 626.

The product of its digits is 2592, while the sum is 30.

The square root of 21166419 is about 4600.6976644852. The cubic root of 21166419 is about 276.6192904475.

The spelling of 21166419 in words is "twenty-one million, one hundred sixty-six thousand, four hundred nineteen".