21168693 has 24 divisors (see below), whose sum is σ = 37634688. Its totient is φ = 11165472.

The previous prime is 21168649. The next prime is 21168701. The reversal of 21168693 is 39686112.

It is not a de Polignac number, because 21168693 - 2¹³ = 21160501 is a prime.

It is a super-2 number, since 2×21168693² = 896227126656498, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21168293) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12105 + ... + 13742.

It is an arithmetic number, because the mean of its divisors is an integer number (1568112).

Almost surely, 2^21168693 is an apocalyptic number.

It is an amenable number.

21168693 is a deficient number, since it is larger than the sum of its proper divisors (16465995).

21168693 is a wasteful number, since it uses less digits than its factorization.

21168693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25873 (or 25870 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 21168693 is about 4600.9447942787. The cubic root of 21168693 is about 276.6291962286.

The spelling of 21168693 in words is "twenty-one million, one hundred sixty-eight thousand, six hundred ninety-three".