21282673 has 4 divisors (see below), whose sum is σ = 21502180. Its totient is φ = 21063168.

The previous prime is 21282671. The next prime is 21282719. The reversal of 21282673 is 37628212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11992369 + 9290304 = 3463^2 + 3048^2 .

It is a cyclic number.

It is not a de Polignac number, because 21282673 - 2¹ = 21282671 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21282671) 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, 109608 + ... + 109801.

It is an arithmetic number, because the mean of its divisors is an integer number (5375545).

Almost surely, 2^21282673 is an apocalyptic number.

It is an amenable number.

21282673 is a deficient number, since it is larger than the sum of its proper divisors (219507).

21282673 is an equidigital number, since it uses as much as digits as its factorization.

21282673 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219506.

The product of its digits is 8064, while the sum is 31.

The square root of 21282673 is about 4613.3147518894. The cubic root of 21282673 is about 277.1247987743.

The spelling of 21282673 in words is "twenty-one million, two hundred eighty-two thousand, six hundred seventy-three".