21167161 has 2 divisors, whose sum is σ = 21167162. Its totient is φ = 21167160.

The previous prime is 21167149. The next prime is 21167171. The reversal of 21167161 is 16176112.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17480761 + 3686400 = 4181^2 + 1920^2 .

It is a cyclic number.

It is not a de Polignac number, because 21167161 - 2²³ = 12778553 is a prime.

It is not a weakly prime, because it can be changed into another prime (21167101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10583580 + 10583581.

It is an arithmetic number, because the mean of its divisors is an integer number (10583581).

Almost surely, 2^21167161 is an apocalyptic number.

It is an amenable number.

21167161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21167161 is an equidigital number, since it uses as much as digits as its factorization.

21167161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 504, while the sum is 25.

The square root of 21167161 is about 4600.7783037221. The cubic root of 21167161 is about 276.6225227548.

The spelling of 21167161 in words is "twenty-one million, one hundred sixty-seven thousand, one hundred sixty-one".