21363273 has 6 divisors (see below), whose sum is σ = 30858074. Its totient is φ = 14242176.

The previous prime is 21363257. The next prime is 21363289. The reversal of 21363273 is 37236312.

21363273 is a `hidden beast` number, since 21 + 3 + 632 + 7 + 3 = 666.

It is an interprime number because it is at equal distance from previous prime (21363257) and next prime (21363289).

It can be written as a sum of positive squares in only one way, i.e., 14768649 + 6594624 = 3843^2 + 2568^2 .

It is not a de Polignac number, because 21363273 - 2⁴ = 21363257 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21363253) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1186840 + ... + 1186857.

Almost surely, 2^21363273 is an apocalyptic number.

It is an amenable number.

21363273 is a deficient number, since it is larger than the sum of its proper divisors (9494801).

21363273 is a wasteful number, since it uses less digits than its factorization.

21363273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2373703 (or 2373700 counting only the distinct ones).

The product of its digits is 4536, while the sum is 27.

The square root of 21363273 is about 4622.0420811585. The cubic root of 21363273 is about 277.4741928764.

Adding to 21363273 its reverse (37236312), we get a palindrome (58599585).

The spelling of 21363273 in words is "twenty-one million, three hundred sixty-three thousand, two hundred seventy-three".