21435816 has 32 divisors (see below), whose sum is σ = 55920960. Its totient is φ = 6834432.

The previous prime is 21435769. The next prime is 21435833. The reversal of 21435816 is 61853412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18865 + ... + 19968.

It is an arithmetic number, because the mean of its divisors is an integer number (1747530).

Almost surely, 2^21435816 is an apocalyptic number.

It is an amenable number.

21435816 is an abundant number, since it is smaller than the sum of its proper divisors (34485144).

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

21435816 is a wasteful number, since it uses less digits than its factorization.

21435816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38865 (or 38861 counting only the distinct ones).

The product of its digits is 5760, while the sum is 30.

The square root of 21435816 is about 4629.8829358851. The cubic root of 21435816 is about 277.7879099356.

The spelling of 21435816 in words is "twenty-one million, four hundred thirty-five thousand, eight hundred sixteen".