21345353 has 4 divisors (see below), whose sum is σ = 22600980. Its totient is φ = 20089728.

The previous prime is 21345349. The next prime is 21345367. The reversal of 21345353 is 35354312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6538249 + 14807104 = 2557^2 + 3848^2 .

It is a cyclic number.

It is not a de Polignac number, because 21345353 - 2² = 21345349 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21345383) 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, 627788 + ... + 627821.

It is an arithmetic number, because the mean of its divisors is an integer number (5650245).

Almost surely, 2^21345353 is an apocalyptic number.

It is an amenable number.

21345353 is a deficient number, since it is larger than the sum of its proper divisors (1255627).

21345353 is a wasteful number, since it uses less digits than its factorization.

21345353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1255626.

The product of its digits is 5400, while the sum is 26.

The square root of 21345353 is about 4620.1031373769. The cubic root of 21345353 is about 277.3965872822.

Adding to 21345353 its reverse (35354312), we get a palindrome (56699665).

The spelling of 21345353 in words is "twenty-one million, three hundred forty-five thousand, three hundred fifty-three".