21166007 has 2 divisors, whose sum is σ = 21166008. Its totient is φ = 21166006.

The previous prime is 21165997. The next prime is 21166009. The reversal of 21166007 is 70066112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21166007 - 2¹² = 21161911 is a prime.

Together with 21166009, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21166009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10583003 + 10583004.

It is an arithmetic number, because the mean of its divisors is an integer number (10583004).

Almost surely, 2^21166007 is an apocalyptic number.

21166007 is a deficient number, since it is larger than the sum of its proper divisors (1).

21166007 is an equidigital number, since it uses as much as digits as its factorization.

21166007 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 504, while the sum is 23.

The square root of 21166007 is about 4600.6528884496. The cubic root of 21166007 is about 276.6174956566.

The spelling of 21166007 in words is "twenty-one million, one hundred sixty-six thousand, seven".