21353347 has 2 divisors, whose sum is σ = 21353348. Its totient is φ = 21353346.

The previous prime is 21353281. The next prime is 21353357. The reversal of 21353347 is 74335312.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21353347 - 2⁷ = 21353219 is a prime.

It is not a weakly prime, because it can be changed into another prime (21353357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10676673 + 10676674.

It is an arithmetic number, because the mean of its divisors is an integer number (10676674).

Almost surely, 2^21353347 is an apocalyptic number.

21353347 is a deficient number, since it is larger than the sum of its proper divisors (1).

21353347 is an equidigital number, since it uses as much as digits as its factorization.

21353347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7560, while the sum is 28.

The square root of 21353347 is about 4620.9681885942. The cubic root of 21353347 is about 277.4312120168.

Adding to 21353347 its reverse (74335312), we get a palindrome (95688659).

The spelling of 21353347 in words is "twenty-one million, three hundred fifty-three thousand, three hundred forty-seven".