21803039 has 2 divisors, whose sum is σ = 21803040. Its totient is φ = 21803038.

The previous prime is 21803003. The next prime is 21803059. The reversal of 21803039 is 93030812.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21803039 is a prime.

It is a super-3 number, since 3×21803039³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21802999 and 21803017.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21803059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10901519 + 10901520.

It is an arithmetic number, because the mean of its divisors is an integer number (10901520).

Almost surely, 2^21803039 is an apocalyptic number.

21803039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21803039 is an equidigital number, since it uses as much as digits as its factorization.

21803039 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 21803039 is about 4669.3724417742. The cubic root of 21803039 is about 279.3652244309.

The spelling of 21803039 in words is "twenty-one million, eight hundred three thousand, thirty-nine".