1386331978 has 16 divisors (see below), whose sum is σ = 2101397760. Its totient is φ = 685883376.

The previous prime is 1386331957. The next prime is 1386331981. The reversal of 1386331978 is 8791336831.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 175551 + ... + 183277.

It is an arithmetic number, because the mean of its divisors is an integer number (131337360).

Almost surely, 2^1386331978 is an apocalyptic number.

1386331978 is a deficient number, since it is larger than the sum of its proper divisors (715065782).

1386331978 is a wasteful number, since it uses less digits than its factorization.

1386331978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8661.

The product of its digits is 653184, while the sum is 49.

The square root of 1386331978 is about 37233.4792626206. The cubic root of 1386331978 is about 1115.0364907253.

The spelling of 1386331978 in words is "one billion, three hundred eighty-six million, three hundred thirty-one thousand, nine hundred seventy-eight".