21058907 has 2 divisors, whose sum is σ = 21058908. Its totient is φ = 21058906.

The previous prime is 21058853. The next prime is 21058931. The reversal of 21058907 is 70985012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21058907 - 2¹² = 21054811 is a prime.

It is a Chen prime.

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

It is not a weakly prime, because it can be changed into another prime (21058987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10529453 + 10529454.

It is an arithmetic number, because the mean of its divisors is an integer number (10529454).

Almost surely, 2^21058907 is an apocalyptic number.

21058907 is a deficient number, since it is larger than the sum of its proper divisors (1).

21058907 is an equidigital number, since it uses as much as digits as its factorization.

21058907 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 21058907 is about 4588.9984746130. The cubic root of 21058907 is about 276.1501449739.

The spelling of 21058907 in words is "twenty-one million, fifty-eight thousand, nine hundred seven".