21165356 has 12 divisors (see below), whose sum is σ = 37105992. Its totient is φ = 10563648.

The previous prime is 21165299. The next prime is 21165379. The reversal of 21165356 is 65356112.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2090 + ... + 6833.

It is an arithmetic number, because the mean of its divisors is an integer number (3092166).

Almost surely, 2^21165356 is an apocalyptic number.

It is an amenable number.

21165356 is a deficient number, since it is larger than the sum of its proper divisors (15940636).

21165356 is a wasteful number, since it uses less digits than its factorization.

21165356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9520 (or 9518 counting only the distinct ones).

The product of its digits is 5400, while the sum is 29.

The square root of 21165356 is about 4600.5821370779. The cubic root of 21165356 is about 276.6146596653.

The spelling of 21165356 in words is "twenty-one million, one hundred sixty-five thousand, three hundred fifty-six".