21039273 has 48 divisors (see below), whose sum is σ = 33860736. Its totient is φ = 12545280.

The previous prime is 21039253. The next prime is 21039281. The reversal of 21039273 is 37293012.

It is not a de Polignac number, because 21039273 - 2¹⁰ = 21038249 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21039233) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 313986 + ... + 314052.

It is an arithmetic number, because the mean of its divisors is an integer number (705432).

Almost surely, 2^21039273 is an apocalyptic number.

21039273 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

It is an amenable number.

21039273 is a deficient number, since it is larger than the sum of its proper divisors (12821463).

21039273 is a wasteful number, since it uses less digits than its factorization.

21039273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 2268, while the sum is 27.

The square root of 21039273 is about 4586.8587290214. The cubic root of 21039273 is about 276.0642966146.

It can be divided in two parts, 21039 and 273, that added together give a palindrome (21312).

The spelling of 21039273 in words is "twenty-one million, thirty-nine thousand, two hundred seventy-three".