21356733 has 16 divisors (see below), whose sum is σ = 29434496. Its totient is φ = 13763520.

The previous prime is 21356723. The next prime is 21356759. The reversal of 21356733 is 33765312.

It is not a de Polignac number, because 21356733 - 2¹³ = 21348541 is a prime.

It is a super-2 number, since 2×21356733² = 912220088866578, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21356733.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21356723) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 19560 + ... + 20622.

It is an arithmetic number, because the mean of its divisors is an integer number (1839656).

Almost surely, 2^21356733 is an apocalyptic number.

It is an amenable number.

21356733 is a deficient number, since it is larger than the sum of its proper divisors (8077763).

21356733 is a wasteful number, since it uses less digits than its factorization.

21356733 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1284.

The product of its digits is 11340, while the sum is 30.

The square root of 21356733 is about 4621.3345475090. The cubic root of 21356733 is about 277.4458753299.

The spelling of 21356733 in words is "twenty-one million, three hundred fifty-six thousand, seven hundred thirty-three".