165167221 has 2 divisors, whose sum is σ = 165167222. Its totient is φ = 165167220.

The previous prime is 165167201. The next prime is 165167227. The reversal of 165167221 is 122761561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123099025 + 42068196 = 11095^2 + 6486^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165167221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165167227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82583610 + 82583611.

It is an arithmetic number, because the mean of its divisors is an integer number (82583611).

Almost surely, 2^165167221 is an apocalyptic number.

It is an amenable number.

165167221 is a deficient number, since it is larger than the sum of its proper divisors (1).

165167221 is an equidigital number, since it uses as much as digits as its factorization.

165167221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5040, while the sum is 31.

The square root of 165167221 is about 12851.7399989262. The cubic root of 165167221 is about 548.6658805303.

The spelling of 165167221 in words is "one hundred sixty-five million, one hundred sixty-seven thousand, two hundred twenty-one".