21168236 has 24 divisors (see below), whose sum is σ = 38216640. Its totient is φ = 10253952.

The previous prime is 21168229. The next prime is 21168239. The reversal of 21168236 is 63286112.

It is a junction number, because it is equal to n+sod(n) for n = 21168199 and 21168208.

It is not an unprimeable number, because it can be changed into a prime (21168239) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19976 + ... + 21008.

It is an arithmetic number, because the mean of its divisors is an integer number (1592360).

Almost surely, 2^21168236 is an apocalyptic number.

It is an amenable number.

21168236 is a deficient number, since it is larger than the sum of its proper divisors (17048404).

21168236 is a wasteful number, since it uses less digits than its factorization.

21168236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1193 (or 1191 counting only the distinct ones).

The product of its digits is 3456, while the sum is 29.

The square root of 21168236 is about 4600.8951302980. The cubic root of 21168236 is about 276.6272055459.

The spelling of 21168236 in words is "twenty-one million, one hundred sixty-eight thousand, two hundred thirty-six".