168190381 has 2 divisors, whose sum is σ = 168190382. Its totient is φ = 168190380.

The previous prime is 168190361. The next prime is 168190387. The reversal of 168190381 is 183091861.

It is the 5295-th star number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 161061481 + 7128900 = 12691^2 + 2670^2 .

It is an emirp because it is prime and its reverse (183091861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 168190381 - 2⁵ = 168190349 is a prime.

It is a super-2 number, since 2×168190381² = 56576008521850322, which contains 22 as substring.

It is a Chen prime.

It is equal to p_9407485 and since 168190381 and 9407485 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 168190381.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168190387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84095190 + 84095191.

It is an arithmetic number, because the mean of its divisors is an integer number (84095191).

Almost surely, 2^168190381 is an apocalyptic number.

It is an amenable number.

168190381 is a deficient number, since it is larger than the sum of its proper divisors (1).

168190381 is an equidigital number, since it uses as much as digits as its factorization.

168190381 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 37.

The square root of 168190381 is about 12968.8234238885. The cubic root of 168190381 is about 551.9931878404.

The spelling of 168190381 in words is "one hundred sixty-eight million, one hundred ninety thousand, three hundred eighty-one".