15664387 has 2 divisors, whose sum is σ = 15664388. Its totient is φ = 15664386.

The previous prime is 15664381. The next prime is 15664391. The reversal of 15664387 is 78346651.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15664387 is a prime.

It is not a weakly prime, because it can be changed into another prime (15664381) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7832193 + 7832194.

It is an arithmetic number, because the mean of its divisors is an integer number (7832194).

Almost surely, 2^15664387 is an apocalyptic number.

15664387 is a deficient number, since it is larger than the sum of its proper divisors (1).

15664387 is an equidigital number, since it uses as much as digits as its factorization.

15664387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 120960, while the sum is 40.

The square root of 15664387 is about 3957.8260446867. The cubic root of 15664387 is about 250.2098877392.

The spelling of 15664387 in words is "fifteen million, six hundred sixty-four thousand, three hundred eighty-seven".