1391278889 has 32 divisors (see below), whose sum is σ = 1911512064. Its totient is φ = 977417280.

The previous prime is 1391278879. The next prime is 1391278897. The reversal of 1391278889 is 9888721931.

It is not a de Polignac number, because 1391278889 - 2⁴ = 1391278873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1391278879) 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 31 ways as a sum of consecutive naturals, for example, 26882 + ... + 59204.

It is an arithmetic number, because the mean of its divisors is an integer number (59734752).

Almost surely, 2^1391278889 is an apocalyptic number.

It is an amenable number.

1391278889 is a deficient number, since it is larger than the sum of its proper divisors (520233175).

1391278889 is a wasteful number, since it uses less digits than its factorization.

1391278889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32397.

The product of its digits is 1741824, while the sum is 56.

The square root of 1391278889 is about 37299.8510586839. The cubic root of 1391278889 is about 1116.3611946595.

The spelling of 1391278889 in words is "one billion, three hundred ninety-one million, two hundred seventy-eight thousand, eight hundred eighty-nine".