15665131 has 2 divisors, whose sum is σ = 15665132. Its totient is φ = 15665130.

The previous prime is 15665129. The next prime is 15665141. The reversal of 15665131 is 13156651.

It is a weak prime.

It is an emirp because it is prime and its reverse (13156651) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15665131 - 2¹ = 15665129 is a prime.

It is a super-2 number, since 2×15665131² = 490792658494322, which contains 22 as substring.

Together with 15665129, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 15665131.

It is not a weakly prime, because it can be changed into another prime (15665141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7832565 + 7832566.

It is an arithmetic number, because the mean of its divisors is an integer number (7832566).

Almost surely, 2^15665131 is an apocalyptic number.

15665131 is a deficient number, since it is larger than the sum of its proper divisors (1).

15665131 is an equidigital number, since it uses as much as digits as its factorization.

15665131 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2700, while the sum is 28.

The square root of 15665131 is about 3957.9200345636. The cubic root of 15665131 is about 250.2138490222.

The spelling of 15665131 in words is "fifteen million, six hundred sixty-five thousand, one hundred thirty-one".