21312835 has 16 divisors (see below), whose sum is σ = 26832960. Its totient is φ = 16220160.

The previous prime is 21312833. The next prime is 21312871. The reversal of 21312835 is 53821312.

It is not a de Polignac number, because 21312835 - 2¹ = 21312833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21312833) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 27331 + ... + 28099.

It is an arithmetic number, because the mean of its divisors is an integer number (1677060).

Almost surely, 2^21312835 is an apocalyptic number.

21312835 is a deficient number, since it is larger than the sum of its proper divisors (5520125).

21312835 is a wasteful number, since it uses less digits than its factorization.

21312835 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1038.

The product of its digits is 1440, while the sum is 25.

The square root of 21312835 is about 4616.5826105465. The cubic root of 21312835 is about 277.2556515833.

The spelling of 21312835 in words is "twenty-one million, three hundred twelve thousand, eight hundred thirty-five".