21803049 has 6 divisors (see below), whose sum is σ = 31493306. Its totient is φ = 14535360.

The previous prime is 21803039. The next prime is 21803059. The reversal of 21803049 is 94030812.

It is an interprime number because it is at equal distance from previous prime (21803039) and next prime (21803059).

It can be written as a sum of positive squares in only one way, i.e., 16257024 + 5546025 = 4032^2 + 2355^2 .

It is not a de Polignac number, because 21803049 - 2⁸ = 21802793 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21803039) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1211272 + ... + 1211289.

Almost surely, 2^21803049 is an apocalyptic number.

It is an amenable number.

21803049 is a deficient number, since it is larger than the sum of its proper divisors (9690257).

21803049 is a wasteful number, since it uses less digits than its factorization.

21803049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2422567 (or 2422564 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 21803049 is about 4669.3735125817. The cubic root of 21803049 is about 279.3652671414.

The spelling of 21803049 in words is "twenty-one million, eight hundred three thousand, forty-nine".