21343651 has 8 divisors (see below), whose sum is σ = 24420704. Its totient is φ = 18273600.

The previous prime is 21343649. The next prime is 21343661. The reversal of 21343651 is 15634312.

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

It is a cyclic number.

It is not a de Polignac number, because 21343651 - 2¹ = 21343649 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21343601) 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, 10951 + ... + 12751.

It is an arithmetic number, because the mean of its divisors is an integer number (3052588).

Almost surely, 2^21343651 is an apocalyptic number.

21343651 is a deficient number, since it is larger than the sum of its proper divisors (3077053).

21343651 is a wasteful number, since it uses less digits than its factorization.

21343651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3501.

The product of its digits is 2160, while the sum is 25.

The square root of 21343651 is about 4619.9189386828. The cubic root of 21343651 is about 277.3892142247.

Adding to 21343651 its reverse (15634312), we get a palindrome (36977963).

The spelling of 21343651 in words is "twenty-one million, three hundred forty-three thousand, six hundred fifty-one".