21351353 has 2 divisors, whose sum is σ = 21351354. Its totient is φ = 21351352.

The previous prime is 21351347. The next prime is 21351361. The reversal of 21351353 is 35315312.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19998784 + 1352569 = 4472^2 + 1163^2 .

It is a cyclic number.

It is not a de Polignac number, because 21351353 - 2⁶ = 21351289 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21351053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10675676 + 10675677.

It is an arithmetic number, because the mean of its divisors is an integer number (10675677).

Almost surely, 2^21351353 is an apocalyptic number.

It is an amenable number.

21351353 is a deficient number, since it is larger than the sum of its proper divisors (1).

21351353 is an equidigital number, since it uses as much as digits as its factorization.

21351353 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1350, while the sum is 23.

The square root of 21351353 is about 4620.7524279061. The cubic root of 21351353 is about 277.4225761332.

Adding to 21351353 its reverse (35315312), we get a palindrome (56666665).

It can be divided in two parts, 21351 and 353, that multiplied together give a triangular number (7536903 = T₃₈₈₂).

The spelling of 21351353 in words is "twenty-one million, three hundred fifty-one thousand, three hundred fifty-three".