1385644778 has 16 divisors (see below), whose sum is σ = 2382575424. Its totient is φ = 592051680.

The previous prime is 1385644769. The next prime is 1385644811. The reversal of 1385644778 is 8774465831.

It is a happy number.

It is a super-2 number, since 2×1385644778² = 3840022901597338568, which contains 22 as substring.

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, 144875 + ... + 154142.

It is an arithmetic number, because the mean of its divisors is an integer number (148910964).

Almost surely, 2^1385644778 is an apocalyptic number.

1385644778 is a deficient number, since it is larger than the sum of its proper divisors (996930646).

1385644778 is a wasteful number, since it uses less digits than its factorization.

1385644778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299357.

The product of its digits is 4515840, while the sum is 53.

The square root of 1385644778 is about 37224.2498648395. The cubic root of 1385644778 is about 1114.8522203550.

The spelling of 1385644778 in words is "one billion, three hundred eighty-five million, six hundred forty-four thousand, seven hundred seventy-eight".