21953167 has 2 divisors, whose sum is σ = 21953168. Its totient is φ = 21953166.

The previous prime is 21953161. The next prime is 21953221. The reversal of 21953167 is 76135912.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21953167 - 2¹⁵ = 21920399 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21953161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10976583 + 10976584.

It is an arithmetic number, because the mean of its divisors is an integer number (10976584).

Almost surely, 2^21953167 is an apocalyptic number.

21953167 is a deficient number, since it is larger than the sum of its proper divisors (1).

21953167 is an equidigital number, since it uses as much as digits as its factorization.

21953167 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 34.

The square root of 21953167 is about 4685.4206854881. The cubic root of 21953167 is about 280.0049616468.

The spelling of 21953167 in words is "twenty-one million, nine hundred fifty-three thousand, one hundred sixty-seven".