168666551 has 2 divisors, whose sum is σ = 168666552. Its totient is φ = 168666550.

The previous prime is 168666539. The next prime is 168666583. The reversal of 168666551 is 155666861.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-168666551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (168669551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 84333275 + 84333276.

It is an arithmetic number, because the mean of its divisors is an integer number (84333276).

Almost surely, 2^168666551 is an apocalyptic number.

168666551 is a deficient number, since it is larger than the sum of its proper divisors (1).

168666551 is an equidigital number, since it uses as much as digits as its factorization.

168666551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 259200, while the sum is 44.

The square root of 168666551 is about 12987.1687060729. The cubic root of 168666551 is about 552.5136197785.

The spelling of 168666551 in words is "one hundred sixty-eight million, six hundred sixty-six thousand, five hundred fifty-one".