168040725409 has 2 divisors, whose sum is σ = 168040725410. Its totient is φ = 168040725408.

The previous prime is 168040725397. The next prime is 168040725497. The reversal of 168040725409 is 904527040861.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166058695009 + 1982030400 = 407503^2 + 44520^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168040725409 is a prime.

It is not a weakly prime, because it can be changed into another prime (168040725709) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84020362704 + 84020362705.

It is an arithmetic number, because the mean of its divisors is an integer number (84020362705).

Almost surely, 2^168040725409 is an apocalyptic number.

It is an amenable number.

168040725409 is a deficient number, since it is larger than the sum of its proper divisors (1).

168040725409 is an equidigital number, since it uses as much as digits as its factorization.

168040725409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 168040725409 in words is "one hundred sixty-eight billion, forty million, seven hundred twenty-five thousand, four hundred nine".