21674916 has 18 divisors (see below), whose sum is σ = 54789462. Its totient is φ = 7224960.

The previous prime is 21674911. The next prime is 21674923. The reversal of 21674916 is 61947612.

21674916 is a `hidden beast` number, since 2 + 167 + 491 + 6 = 666.

It can be written as a sum of positive squares in only one way, i.e., 15444900 + 6230016 = 3930^2 + 2496^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 602081 = 21674916 / (2 + 1 + 6 + 7 + 4 + 9 + 1 + 6).

It is not an unprimeable number, because it can be changed into a prime (21674911) 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 5 ways as a sum of consecutive naturals, for example, 301005 + ... + 301076.

It is an arithmetic number, because the mean of its divisors is an integer number (3043859).

Almost surely, 2^21674916 is an apocalyptic number.

It is an amenable number.

21674916 is an abundant number, since it is smaller than the sum of its proper divisors (33114546).

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

21674916 is a wasteful number, since it uses less digits than its factorization.

21674916 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 602091 (or 602086 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 21674916 is about 4655.6327174725. The cubic root of 21674916 is about 278.8169300429.

The spelling of 21674916 in words is "twenty-one million, six hundred seventy-four thousand, nine hundred sixteen".