21166120 has 16 divisors (see below), whose sum is σ = 47623860. Its totient is φ = 8466432.

The previous prime is 21166111. The next prime is 21166129. The reversal of 21166120 is 2166112.

It is an interprime number because it is at equal distance from previous prime (21166111) and next prime (21166129).

It can be written as a sum of positive squares in 2 ways, for example, as 20994724 + 171396 = 4582^2 + 414^2 .

It is not an unprimeable number, because it can be changed into a prime (21166129) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 264537 + ... + 264616.

Almost surely, 2^21166120 is an apocalyptic number.

21166120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21166120 is an abundant number, since it is smaller than the sum of its proper divisors (26457740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21166120 is a wasteful number, since it uses less digits than its factorization.

21166120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529164 (or 529160 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21166120 is about 4600.6651692989. The cubic root of 21166120 is about 276.6179879195.

The spelling of 21166120 in words is "twenty-one million, one hundred sixty-six thousand, one hundred twenty".