1397578705 has 4 divisors (see below), whose sum is σ = 1677094452. Its totient is φ = 1118062960.

The previous prime is 1397578703. The next prime is 1397578709. The reversal of 1397578705 is 5078757931.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 288422289 + 1109156416 = 16983^2 + 33304^2 .

It is not a de Polignac number, because 1397578705 - 2¹ = 1397578703 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1397578703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139757866 + ... + 139757875.

It is an arithmetic number, because the mean of its divisors is an integer number (419273613).

Almost surely, 2^1397578705 is an apocalyptic number.

It is an amenable number.

1397578705 is a deficient number, since it is larger than the sum of its proper divisors (279515747).

1397578705 is an equidigital number, since it uses as much as digits as its factorization.

1397578705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279515746.

The product of its (nonzero) digits is 1852200, while the sum is 52.

The square root of 1397578705 is about 37384.2039503317. The cubic root of 1397578705 is about 1118.0436470832.

The spelling of 1397578705 in words is "one billion, three hundred ninety-seven million, five hundred seventy-eight thousand, seven hundred five".