166387919 has 2 divisors, whose sum is σ = 166387920. Its totient is φ = 166387918.

The previous prime is 166387901. The next prime is 166387939. The reversal of 166387919 is 919783661.

It is a weak prime.

It is an emirp because it is prime and its reverse (919783661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166387919 is a prime.

It is a super-2 number, since 2×166387919² = 55369879178301122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166387939) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83193959 + 83193960.

It is an arithmetic number, because the mean of its divisors is an integer number (83193960).

Almost surely, 2^166387919 is an apocalyptic number.

166387919 is a deficient number, since it is larger than the sum of its proper divisors (1).

166387919 is an equidigital number, since it uses as much as digits as its factorization.

166387919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 489888, while the sum is 50.

The square root of 166387919 is about 12899.1441188941. The cubic root of 166387919 is about 550.0142354442.

The spelling of 166387919 in words is "one hundred sixty-six million, three hundred eighty-seven thousand, nine hundred nineteen".