21435634 has 24 divisors (see below), whose sum is σ = 35732844. Its totient is φ = 9636000.

The previous prime is 21435593. The next prime is 21435643. The reversal of 21435634 is 43653412.

It can be written as a sum of positive squares in 2 ways, for example, as 16834609 + 4601025 = 4103^2 + 2145^2 .

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 24004 + ... + 24880.

Almost surely, 2^21435634 is an apocalyptic number.

21435634 is a deficient number, since it is larger than the sum of its proper divisors (14297210).

21435634 is a wasteful number, since it uses less digits than its factorization.

21435634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1002 (or 991 counting only the distinct ones).

The product of its digits is 8640, while the sum is 28.

The square root of 21435634 is about 4629.8632809188. The cubic root of 21435634 is about 277.7871237507.

It can be divided in two parts, 2143 and 5634, that added together give a palindrome (7777).

The spelling of 21435634 in words is "twenty-one million, four hundred thirty-five thousand, six hundred thirty-four".