21835684 has 36 divisors (see below), whose sum is σ = 43745044. Its totient is φ = 9478656.

The previous prime is 21835663. The next prime is 21835699. The reversal of 21835684 is 48653812.

It is a happy number.

It can be written as a sum of positive squares in 6 ways, for example, as 3534400 + 18301284 = 1880^2 + 4278^2 .

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 14302 + ... + 15754.

Almost surely, 2^21835684 is an apocalyptic number.

It is an amenable number.

21835684 is an abundant number, since it is smaller than the sum of its proper divisors (21909360).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21835684 is a wasteful number, since it uses less digits than its factorization.

21835684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1504 (or 1485 counting only the distinct ones).

The product of its digits is 46080, while the sum is 37.

The square root of 21835684 is about 4672.8667860319. The cubic root of 21835684 is about 279.5045831368.

The spelling of 21835684 in words is "twenty-one million, eight hundred thirty-five thousand, six hundred eighty-four".