1397126909 has 4 divisors (see below), whose sum is σ = 1398661440. Its totient is φ = 1395592380.

The previous prime is 1397126869. The next prime is 1397126911. The reversal of 1397126909 is 9096217931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 9096217931 = 17 ⋅535071643.

It is a cyclic number.

It is not a de Polignac number, because 1397126909 - 2¹⁶ = 1397061373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1397126989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 765899 + ... + 767720.

It is an arithmetic number, because the mean of its divisors is an integer number (349665360).

Almost surely, 2^1397126909 is an apocalyptic number.

It is an amenable number.

1397126909 is a deficient number, since it is larger than the sum of its proper divisors (1534531).

1397126909 is an equidigital number, since it uses as much as digits as its factorization.

1397126909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1534530.

The product of its (nonzero) digits is 183708, while the sum is 47.

The square root of 1397126909 is about 37378.1608563075. The cubic root of 1397126909 is about 1117.9231572468.

The spelling of 1397126909 in words is "one billion, three hundred ninety-seven million, one hundred twenty-six thousand, nine hundred nine".