21293273 has 2 divisors, whose sum is σ = 21293274. Its totient is φ = 21293272.

The previous prime is 21293263. The next prime is 21293317. The reversal of 21293273 is 37239212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13520329 + 7772944 = 3677^2 + 2788^2 .

It is a cyclic number.

It is not a de Polignac number, because 21293273 - 2⁴ = 21293257 is a prime.

It is a super-3 number, since 3×21293273³ (a number of 23 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21293263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10646636 + 10646637.

It is an arithmetic number, because the mean of its divisors is an integer number (10646637).

Almost surely, 2^21293273 is an apocalyptic number.

It is an amenable number.

21293273 is a deficient number, since it is larger than the sum of its proper divisors (1).

21293273 is an equidigital number, since it uses as much as digits as its factorization.

21293273 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 29.

The square root of 21293273 is about 4614.4634574347. The cubic root of 21293273 is about 277.1707991884.

The spelling of 21293273 in words is "twenty-one million, two hundred ninety-three thousand, two hundred seventy-three".