166621379 has 2 divisors, whose sum is σ = 166621380. Its totient is φ = 166621378.

The previous prime is 166621337. The next prime is 166621387. The reversal of 166621379 is 973126661.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166621379 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (166621979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83310689 + 83310690.

It is an arithmetic number, because the mean of its divisors is an integer number (83310690).

Almost surely, 2^166621379 is an apocalyptic number.

166621379 is a deficient number, since it is larger than the sum of its proper divisors (1).

166621379 is an equidigital number, since it uses as much as digits as its factorization.

166621379 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 41.

The square root of 166621379 is about 12908.1903844032. The cubic root of 166621379 is about 550.2713581068.

The spelling of 166621379 in words is "one hundred sixty-six million, six hundred twenty-one thousand, three hundred seventy-nine".