168225661 has 2 divisors, whose sum is σ = 168225662. Its totient is φ = 168225660.

The previous prime is 168225649. The next prime is 168225679. The reversal of 168225661 is 166522861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 168220900 + 4761 = 12970^2 + 69^2 .

It is an emirp because it is prime and its reverse (166522861) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 168225661 - 2¹¹ = 168223613 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 168225661.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168225641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84112830 + 84112831.

It is an arithmetic number, because the mean of its divisors is an integer number (84112831).

Almost surely, 2^168225661 is an apocalyptic number.

It is an amenable number.

168225661 is a deficient number, since it is larger than the sum of its proper divisors (1).

168225661 is an equidigital number, since it uses as much as digits as its factorization.

168225661 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 37.

The square root of 168225661 is about 12970.1835376374. The cubic root of 168225661 is about 552.0317809277.

The spelling of 168225661 in words is "one hundred sixty-eight million, two hundred twenty-five thousand, six hundred sixty-one".