21707033 has 4 divisors (see below), whose sum is σ = 22062948. Its totient is φ = 21351120.

The previous prime is 21707003. The next prime is 21707041. The reversal of 21707033 is 33070712.

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 4376464 + 17330569 = 2092^2 + 4163^2 .

It is a cyclic number.

It is not a de Polignac number, because 21707033 - 2⁸ = 21706777 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21707003) 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, 177866 + ... + 177987.

It is an arithmetic number, because the mean of its divisors is an integer number (5515737).

Almost surely, 2^21707033 is an apocalyptic number.

It is an amenable number.

21707033 is a deficient number, since it is larger than the sum of its proper divisors (355915).

21707033 is an equidigital number, since it uses as much as digits as its factorization.

21707033 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355914.

The product of its (nonzero) digits is 882, while the sum is 23.

The square root of 21707033 is about 4659.0807033148. The cubic root of 21707033 is about 278.9545752368.

Adding to 21707033 its reverse (33070712), we get a palindrome (54777745).

The spelling of 21707033 in words is "twenty-one million, seven hundred seven thousand, thirty-three".