21116493 has 6 divisors (see below), whose sum is σ = 30501614. Its totient is φ = 14077656.

The previous prime is 21116479. The next prime is 21116503. The reversal of 21116493 is 39461112.

21116493 is a `hidden beast` number, since 2 + 1 + 11 + 649 + 3 = 666.

It can be written as a sum of positive squares in only one way, i.e., 11269449 + 9847044 = 3357^2 + 3138^2 .

It is not a de Polignac number, because 21116493 - 2⁴ = 21116477 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 (21116453) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1173130 + ... + 1173147.

Almost surely, 2^21116493 is an apocalyptic number.

It is an amenable number.

21116493 is a deficient number, since it is larger than the sum of its proper divisors (9385121).

21116493 is a wasteful number, since it uses less digits than its factorization.

21116493 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2346283 (or 2346280 counting only the distinct ones).

The product of its digits is 1296, while the sum is 27.

The square root of 21116493 is about 4595.2685449275. The cubic root of 21116493 is about 276.4016285718.

It can be divided in two parts, 21116 and 493, that added together give a square (21609 = 147²).

The spelling of 21116493 in words is "twenty-one million, one hundred sixteen thousand, four hundred ninety-three".