166852421 has 2 divisors, whose sum is σ = 166852422. Its totient is φ = 166852420.

The previous prime is 166852417. The next prime is 166852423. The reversal of 166852421 is 124258661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118048225 + 48804196 = 10865^2 + 6986^2 .

It is a cyclic number.

It is not a de Polignac number, because 166852421 - 2² = 166852417 is a prime.

It is a super-2 number, since 2×166852421² = 55679460787122482, which contains 22 as substring.

Together with 166852423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166852423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83426210 + 83426211.

It is an arithmetic number, because the mean of its divisors is an integer number (83426211).

Almost surely, 2^166852421 is an apocalyptic number.

166852421 is the 6905-th centered heptagonal number.

It is an amenable number.

166852421 is a deficient number, since it is larger than the sum of its proper divisors (1).

166852421 is an equidigital number, since it uses as much as digits as its factorization.

166852421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23040, while the sum is 35.

The square root of 166852421 is about 12917.1367183289. The cubic root of 166852421 is about 550.5255813398.

The spelling of 166852421 in words is "one hundred sixty-six million, eight hundred fifty-two thousand, four hundred twenty-one".