21673307 has 2 divisors, whose sum is σ = 21673308. Its totient is φ = 21673306.

The previous prime is 21673303. The next prime is 21673331. The reversal of 21673307 is 70337612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21673307 - 2² = 21673303 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21673307.

It is not a weakly prime, because it can be changed into another prime (21673303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10836653 + 10836654.

It is an arithmetic number, because the mean of its divisors is an integer number (10836654).

Almost surely, 2^21673307 is an apocalyptic number.

21673307 is a deficient number, since it is larger than the sum of its proper divisors (1).

21673307 is an equidigital number, since it uses as much as digits as its factorization.

21673307 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 29.

The square root of 21673307 is about 4655.4599128335. The cubic root of 21673307 is about 278.8100307076.

The spelling of 21673307 in words is "twenty-one million, six hundred seventy-three thousand, three hundred seven".