1386668644 has 27 divisors (see below), whose sum is σ = 2490167673. Its totient is φ = 675646272.

The previous prime is 1386668639. The next prime is 1386668663. The reversal of 1386668644 is 4468666831.

The square root of 1386668644 is 37238.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 155500900 + 1231167744 = 12470^2 + 35088^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1386668591 and 1386668600.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3202252 + ... + 3202684.

Almost surely, 2^1386668644 is an apocalyptic number.

1386668644 is the 37238-th square number.

It is an amenable number.

1386668644 is a deficient number, since it is larger than the sum of its proper divisors (1103499029).

1386668644 is an frugal number, since it uses more digits than its factorization.

1386668644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 956 (or 478 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 52.

The cubic root of 1386668644 is about 1115.1267443580.

The spelling of 1386668644 in words is "one billion, three hundred eighty-six million, six hundred sixty-eight thousand, six hundred forty-four".