21302147 has 2 divisors, whose sum is σ = 21302148. Its totient is φ = 21302146.

The previous prime is 21302143. The next prime is 21302161. The reversal of 21302147 is 74120312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21302147 - 2² = 21302143 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21302143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10651073 + 10651074.

It is an arithmetic number, because the mean of its divisors is an integer number (10651074).

Almost surely, 2^21302147 is an apocalyptic number.

21302147 is a deficient number, since it is larger than the sum of its proper divisors (1).

21302147 is an equidigital number, since it uses as much as digits as its factorization.

21302147 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 21302147 is about 4615.4248991832. The cubic root of 21302147 is about 277.2092976079.

Adding to 21302147 its reverse (74120312), we get a palindrome (95422459).

The spelling of 21302147 in words is "twenty-one million, three hundred two thousand, one hundred forty-seven".