21010307 has 2 divisors, whose sum is σ = 21010308. Its totient is φ = 21010306.

The previous prime is 21010271. The next prime is 21010321. The reversal of 21010307 is 70301012.

It is an a-pointer prime, because the next prime (21010321) can be obtained adding 21010307 to its sum of digits (14).

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21010307 - 2¹⁰ = 21009283 is a prime.

It is a Chen prime.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21010291 and 21010300.

It is not a weakly prime, because it can be changed into another prime (21010337) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10505153 + 10505154.

It is an arithmetic number, because the mean of its divisors is an integer number (10505154).

Almost surely, 2^21010307 is an apocalyptic number.

21010307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21010307 is an equidigital number, since it uses as much as digits as its factorization.

21010307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 42, while the sum is 14.

The square root of 21010307 is about 4583.7001428977. The cubic root of 21010307 is about 275.9375471310.

Adding to 21010307 its reverse (70301012), we get a palindrome (91311319).

The spelling of 21010307 in words is "twenty-one million, ten thousand, three hundred seven".