15666379 has 2 divisors, whose sum is σ = 15666380. Its totient is φ = 15666378.

The previous prime is 15666359. The next prime is 15666397. The reversal of 15666379 is 97366651.

Together with next prime (15666397) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15666379 is a prime.

It is not a weakly prime, because it can be changed into another prime (15666349) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7833189 + 7833190.

It is an arithmetic number, because the mean of its divisors is an integer number (7833190).

Almost surely, 2^15666379 is an apocalyptic number.

15666379 is a deficient number, since it is larger than the sum of its proper divisors (1).

15666379 is an equidigital number, since it uses as much as digits as its factorization.

15666379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 204120, while the sum is 43.

The square root of 15666379 is about 3958.0776899904. The cubic root of 15666379 is about 250.2204934733.

The spelling of 15666379 in words is "fifteen million, six hundred sixty-six thousand, three hundred seventy-nine".