1397378817 has 8 divisors (see below), whose sum is σ = 2070190880. Its totient is φ = 931585860.

The previous prime is 1397378813. The next prime is 1397378819. The reversal of 1397378817 is 7188737931.

It is a happy number.

It is not a de Polignac number, because 1397378817 - 2² = 1397378813 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1397378813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 25877359 + ... + 25877412.

It is an arithmetic number, because the mean of its divisors is an integer number (258773860).

Almost surely, 2^1397378817 is an apocalyptic number.

It is an amenable number.

1397378817 is a deficient number, since it is larger than the sum of its proper divisors (672812063).

1397378817 is an equidigital number, since it uses as much as digits as its factorization.

1397378817 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51754780 (or 51754774 counting only the distinct ones).

The product of its digits is 1778112, while the sum is 54.

The square root of 1397378817 is about 37381.5304261342. The cubic root of 1397378817 is about 1117.9903419960.

The spelling of 1397378817 in words is "one billion, three hundred ninety-seven million, three hundred seventy-eight thousand, eight hundred seventeen".