21166480 has 20 divisors (see below), whose sum is σ = 49212252. Its totient is φ = 8466560.

The previous prime is 21166471. The next prime is 21166487. The reversal of 21166480 is 8466112.

It can be written as a sum of positive squares in 2 ways, for example, as 8549776 + 12616704 = 2924^2 + 3552^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (21166487) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 132211 + ... + 132370.

Almost surely, 2^21166480 is an apocalyptic number.

21166480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21166480 is an abundant number, since it is smaller than the sum of its proper divisors (28045772).

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

21166480 is a wasteful number, since it uses less digits than its factorization.

21166480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 264594 (or 264588 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21166480 is about 4600.7042939098. The cubic root of 21166480 is about 276.6195561791.

The spelling of 21166480 in words is "twenty-one million, one hundred sixty-six thousand, four hundred eighty".