21354786 has 16 divisors (see below), whose sum is σ = 47455200. Its totient is φ = 7118244.

The previous prime is 21354721. The next prime is 21354797. The reversal of 21354786 is 68745312.

It is a self number, because there is not a number n which added to its sum of digits gives 21354786.

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, 197676 + ... + 197783.

It is an arithmetic number, because the mean of its divisors is an integer number (2965950).

Almost surely, 2^21354786 is an apocalyptic number.

21354786 is an abundant number, since it is smaller than the sum of its proper divisors (26100414).

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

21354786 is a wasteful number, since it uses less digits than its factorization.

21354786 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 395470 (or 395464 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 21354786 is about 4621.1238892720. The cubic root of 21354786 is about 277.4374438977.

The spelling of 21354786 in words is "twenty-one million, three hundred fifty-four thousand, seven hundred eighty-six".