21166893 has 64 divisors (see below), whose sum is σ = 37478400. Its totient is φ = 11761200.

The previous prime is 21166891. The next prime is 21166903. The reversal of 21166893 is 39866112.

It is not a de Polignac number, because 21166893 - 2¹ = 21166891 is a prime.

Its product of digits (15552) is a multiple of the sum of its prime divisors (64).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21166891) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 682788 + ... + 682818.

It is an arithmetic number, because the mean of its divisors is an integer number (585600).

Almost surely, 2^21166893 is an apocalyptic number.

It is an amenable number.

21166893 is a deficient number, since it is larger than the sum of its proper divisors (16311507).

21166893 is a wasteful number, since it uses less digits than its factorization.

21166893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92 (or 64 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 21166893 is about 4600.7491781231. The cubic root of 21166893 is about 276.6213552994.

It can be divided in two parts, 2116 and 6893, that added together give a palindrome (9009).

The spelling of 21166893 in words is "twenty-one million, one hundred sixty-six thousand, eight hundred ninety-three".