1366125991 has 2 divisors, whose sum is σ = 1366125992. Its totient is φ = 1366125990.

The previous prime is 1366125979. The next prime is 1366126037. The reversal of 1366125991 is 1995216631.

It is a weak prime.

It is an emirp because it is prime and its reverse (1995216631) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1366125991 - 2¹⁹ = 1365601703 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1366125911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 683062995 + 683062996.

It is an arithmetic number, because the mean of its divisors is an integer number (683062996).

Almost surely, 2^1366125991 is an apocalyptic number.

1366125991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1366125991 is an equidigital number, since it uses as much as digits as its factorization.

1366125991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 87480, while the sum is 43.

The square root of 1366125991 is about 36961.1416355069. The cubic root of 1366125991 is about 1109.5926841977.

The spelling of 1366125991 in words is "one billion, three hundred sixty-six million, one hundred twenty-five thousand, nine hundred ninety-one".