15615666191 has 2 divisors, whose sum is σ = 15615666192. Its totient is φ = 15615666190.

The previous prime is 15615666139. The next prime is 15615666193. The reversal of 15615666191 is 19166651651.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 15615666191 - 2¹⁸ = 15615404047 is a prime.

Together with 15615666193, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15615666193) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7807833095 + 7807833096.

It is an arithmetic number, because the mean of its divisors is an integer number (7807833096).

Almost surely, 2^15615666191 is an apocalyptic number.

15615666191 is a deficient number, since it is larger than the sum of its proper divisors (1).

15615666191 is an equidigital number, since it uses as much as digits as its factorization.

15615666191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 291600, while the sum is 47.

The spelling of 15615666191 in words is "fifteen billion, six hundred fifteen million, six hundred sixty-six thousand, one hundred ninety-one".