21202039 has 2 divisors, whose sum is σ = 21202040. Its totient is φ = 21202038.

The previous prime is 21202037. The next prime is 21202079. The reversal of 21202039 is 93020212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21202039 - 2¹ = 21202037 is a prime.

Together with 21202037, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21202033) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601019 + 10601020.

It is an arithmetic number, because the mean of its divisors is an integer number (10601020).

Almost surely, 2^21202039 is an apocalyptic number.

21202039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202039 is an equidigital number, since it uses as much as digits as its factorization.

21202039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 21202039 is about 4604.5671892155. The cubic root of 21202039 is about 276.7743734768.

It can be divided in two parts, 2120203 and 9, that added together give a palindrome (2120212).

The spelling of 21202039 in words is "twenty-one million, two hundred two thousand, thirty-nine".