21163936 has 12 divisors (see below), whose sum is σ = 41666562. Its totient is φ = 10581952.

The previous prime is 21163927. The next prime is 21163957. The reversal of 21163936 is 63936112.

It can be written as a sum of positive squares in only one way, i.e., 20250000 + 913936 = 4500^2 + 956^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21163898 and 21163907.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330655 + ... + 330718.

Almost surely, 2^21163936 is an apocalyptic number.

It is an amenable number.

21163936 is a deficient number, since it is larger than the sum of its proper divisors (20502626).

21163936 is an equidigital number, since it uses as much as digits as its factorization.

21163936 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661383 (or 661375 counting only the distinct ones).

The product of its digits is 5832, while the sum is 31.

The square root of 21163936 is about 4600.4278061937. The cubic root of 21163936 is about 276.6084734303.

The spelling of 21163936 in words is "twenty-one million, one hundred sixty-three thousand, nine hundred thirty-six".