21038285 has 4 divisors (see below), whose sum is σ = 25245948. Its totient is φ = 16830624.

The previous prime is 21038273. The next prime is 21038291. The reversal of 21038285 is 58283012.

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 7941124 + 13097161 = 2818^2 + 3619^2 .

It is a cyclic number.

It is not a de Polignac number, because 21038285 - 2¹⁸ = 20776141 is a prime.

It is a super-3 number, since 3×21038285³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2103824 + ... + 2103833.

It is an arithmetic number, because the mean of its divisors is an integer number (6311487).

Almost surely, 2^21038285 is an apocalyptic number.

It is an amenable number.

21038285 is a deficient number, since it is larger than the sum of its proper divisors (4207663).

21038285 is an equidigital number, since it uses as much as digits as its factorization.

21038285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4207662.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 21038285 is about 4586.7510287784. The cubic root of 21038285 is about 276.0599752391.

The spelling of 21038285 in words is "twenty-one million, thirty-eight thousand, two hundred eighty-five".