21283337 has 4 divisors (see below), whose sum is σ = 22535316. Its totient is φ = 20031360.

The previous prime is 21283333. The next prime is 21283351. The reversal of 21283337 is 73338212.

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 9096256 + 12187081 = 3016^2 + 3491^2 .

It is a cyclic number.

It is not a de Polignac number, because 21283337 - 2² = 21283333 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21283331) 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, 625964 + ... + 625997.

It is an arithmetic number, because the mean of its divisors is an integer number (5633829).

Almost surely, 2^21283337 is an apocalyptic number.

It is an amenable number.

21283337 is a deficient number, since it is larger than the sum of its proper divisors (1251979).

21283337 is a wasteful number, since it uses less digits than its factorization.

21283337 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1251978.

The product of its digits is 6048, while the sum is 29.

The square root of 21283337 is about 4613.3867169358. The cubic root of 21283337 is about 277.1276807580.

The spelling of 21283337 in words is "twenty-one million, two hundred eighty-three thousand, three hundred thirty-seven".