1399641109 has 2 divisors, whose sum is σ = 1399641110. Its totient is φ = 1399641108.

The previous prime is 1399641107. The next prime is 1399641151. The reversal of 1399641109 is 9011469931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 956664900 + 442976209 = 30930^2 + 21047^2 .

It is a cyclic number.

It is not a de Polignac number, because 1399641109 - 2¹ = 1399641107 is a prime.

Together with 1399641107, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1399641107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 699820554 + 699820555.

It is an arithmetic number, because the mean of its divisors is an integer number (699820555).

Almost surely, 2^1399641109 is an apocalyptic number.

It is an amenable number.

1399641109 is a deficient number, since it is larger than the sum of its proper divisors (1).

1399641109 is an equidigital number, since it uses as much as digits as its factorization.

1399641109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52488, while the sum is 43.

The square root of 1399641109 is about 37411.7776776245. Note that the first 3 decimals coincide. The cubic root of 1399641109 is about 1118.5933416754.

The spelling of 1399641109 in words is "one billion, three hundred ninety-nine million, six hundred forty-one thousand, one hundred nine".