168653521 has 2 divisors, whose sum is σ = 168653522. Its totient is φ = 168653520.

The previous prime is 168653497. The next prime is 168653543. The reversal of 168653521 is 125356861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121881600 + 46771921 = 11040^2 + 6839^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168653521 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (168653591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84326760 + 84326761.

It is an arithmetic number, because the mean of its divisors is an integer number (84326761).

Almost surely, 2^168653521 is an apocalyptic number.

It is an amenable number.

168653521 is a deficient number, since it is larger than the sum of its proper divisors (1).

168653521 is an equidigital number, since it uses as much as digits as its factorization.

168653521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 37.

The square root of 168653521 is about 12986.6670473990. The cubic root of 168653521 is about 552.4993916307.

The spelling of 168653521 in words is "one hundred sixty-eight million, six hundred fifty-three thousand, five hundred twenty-one".