21159386 has 16 divisors (see below), whose sum is σ = 33180840. Its totient is φ = 10106880.

The previous prime is 21159377. The next prime is 21159389. The reversal of 21159386 is 68395112.

It can be written as a sum of positive squares in 4 ways, for example, as 17430625 + 3728761 = 4175^2 + 1931^2 .

It is not an unprimeable number, because it can be changed into a prime (21159389) 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, 3746 + ... + 7506.

Almost surely, 2^21159386 is an apocalyptic number.

21159386 is a deficient number, since it is larger than the sum of its proper divisors (12021454).

21159386 is a wasteful number, since it uses less digits than its factorization.

21159386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3889.

The product of its digits is 12960, while the sum is 35.

The square root of 21159386 is about 4599.9332603854. The cubic root of 21159386 is about 276.5886494751.

The spelling of 21159386 in words is "twenty-one million, one hundred fifty-nine thousand, three hundred eighty-six".