21463836 has 12 divisors (see below), whose sum is σ = 50082312. Its totient is φ = 7154608.

The previous prime is 21463831. The next prime is 21463847. The reversal of 21463836 is 63836412.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21463797 and 21463806.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21463831) 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 3 ways as a sum of consecutive naturals, for example, 894315 + ... + 894338.

It is an arithmetic number, because the mean of its divisors is an integer number (4173526).

Almost surely, 2^21463836 is an apocalyptic number.

It is an amenable number.

21463836 is an abundant number, since it is smaller than the sum of its proper divisors (28618476).

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

21463836 is a wasteful number, since it uses less digits than its factorization.

21463836 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1788660 (or 1788658 counting only the distinct ones).

The product of its digits is 20736, while the sum is 33.

The square root of 21463836 is about 4632.9079421029. The cubic root of 21463836 is about 277.9088948054.

The spelling of 21463836 in words is "twenty-one million, four hundred sixty-three thousand, eight hundred thirty-six".