21135634 has 16 divisors (see below), whose sum is σ = 34218072. Its totient is φ = 9733248.

The previous prime is 21135613. The next prime is 21135637. The reversal of 21135634 is 43653112.

It can be written as a sum of positive squares in 4 ways, for example, as 8139609 + 12996025 = 2853^2 + 3605^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21135599 and 21135608.

It is not an unprimeable number, because it can be changed into a prime (21135637) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21702 + ... + 22654.

Almost surely, 2^21135634 is an apocalyptic number.

21135634 is a deficient number, since it is larger than the sum of its proper divisors (13082438).

21135634 is a wasteful number, since it uses less digits than its factorization.

21135634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1821.

The product of its digits is 2160, while the sum is 25.

The square root of 21135634 is about 4597.3507588610. The cubic root of 21135634 is about 276.4851179060.

Adding to 21135634 its reverse (43653112), we get a palindrome (64788746).

The spelling of 21135634 in words is "twenty-one million, one hundred thirty-five thousand, six hundred thirty-four".