21252167 has 2 divisors, whose sum is σ = 21252168. Its totient is φ = 21252166.

The previous prime is 21252151. The next prime is 21252211. The reversal of 21252167 is 76125212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21252167 - 2⁴ = 21252151 is a prime.

It is a Chen prime.

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

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21252107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10626083 + 10626084.

It is an arithmetic number, because the mean of its divisors is an integer number (10626084).

Almost surely, 2^21252167 is an apocalyptic number.

21252167 is a deficient number, since it is larger than the sum of its proper divisors (1).

21252167 is an equidigital number, since it uses as much as digits as its factorization.

21252167 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1680, while the sum is 26.

The square root of 21252167 is about 4610.0072668056. The cubic root of 21252167 is about 276.9923277643.

Adding to 21252167 its reverse (76125212), we get a palindrome (97377379).

The spelling of 21252167 in words is "twenty-one million, two hundred fifty-two thousand, one hundred sixty-seven".