167664821 has 2 divisors, whose sum is σ = 167664822. Its totient is φ = 167664820.

The previous prime is 167664803. The next prime is 167664851. The reversal of 167664821 is 128466761.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93876721 + 73788100 = 9689^2 + 8590^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-167664821 is a prime.

It is a super-2 number, since 2×167664821² = 56222984401924082, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (167664851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83832410 + 83832411.

It is an arithmetic number, because the mean of its divisors is an integer number (83832411).

Almost surely, 2^167664821 is an apocalyptic number.

It is an amenable number.

167664821 is a deficient number, since it is larger than the sum of its proper divisors (1).

167664821 is an equidigital number, since it uses as much as digits as its factorization.

167664821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 41.

The square root of 167664821 is about 12948.5451306315. The cubic root of 167664821 is about 551.4176332478.

The spelling of 167664821 in words is "one hundred sixty-seven million, six hundred sixty-four thousand, eight hundred twenty-one".