21036634 has 8 divisors (see below), whose sum is σ = 31603860. Its totient is φ = 10502016.

The previous prime is 21036623. The next prime is 21036637. The reversal of 21036634 is 43663012.

It can be written as a sum of positive squares in 2 ways, for example, as 19333609 + 1703025 = 4397^2 + 1305^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 21036599 and 21036608.

It is not an unprimeable number, because it can be changed into a prime (21036637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6469 + ... + 9160.

Almost surely, 2^21036634 is an apocalyptic number.

21036634 is a deficient number, since it is larger than the sum of its proper divisors (10567226).

21036634 is a wasteful number, since it uses less digits than its factorization.

21036634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16304.

The product of its (nonzero) digits is 2592, while the sum is 25.

The square root of 21036634 is about 4586.5710503600. The cubic root of 21036634 is about 276.0527536913.

Adding to 21036634 its reverse (43663012), we get a palindrome (64699646).

The spelling of 21036634 in words is "twenty-one million, thirty-six thousand, six hundred thirty-four".