21351369 has 8 divisors (see below), whose sum is σ = 30658432. Its totient is φ = 13139280.

The previous prime is 21351361. The next prime is 21351389. The reversal of 21351369 is 96315312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21351369 - 2³ = 21351361 is a prime.

It is a super-3 number, since 3×21351369³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21351361) 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 7 ways as a sum of consecutive naturals, for example, 273697 + ... + 273774.

It is an arithmetic number, because the mean of its divisors is an integer number (3832304).

Almost surely, 2^21351369 is an apocalyptic number.

It is an amenable number.

21351369 is a deficient number, since it is larger than the sum of its proper divisors (9307063).

21351369 is a wasteful number, since it uses less digits than its factorization.

21351369 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547487.

The product of its digits is 4860, while the sum is 30.

The square root of 21351369 is about 4620.7541592255. The cubic root of 21351369 is about 277.4226454303.

The spelling of 21351369 in words is "twenty-one million, three hundred fifty-one thousand, three hundred sixty-nine".