1384865781 has 16 divisors (see below), whose sum is σ = 2105498304. Its totient is φ = 802093824.

The previous prime is 1384865761. The next prime is 1384865791. The reversal of 1384865781 is 1875684831.

It is a happy number.

It is not a de Polignac number, because 1384865781 - 2⁷ = 1384865653 is a prime.

It is a super-2 number, since 2×1384865781² = 3835706462769479922, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1384865701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1043731 + ... + 1045056.

It is an arithmetic number, because the mean of its divisors is an integer number (131593644).

Almost surely, 2^1384865781 is an apocalyptic number.

It is an amenable number.

1384865781 is a deficient number, since it is larger than the sum of its proper divisors (720632523).

1384865781 is a wasteful number, since it uses less digits than its factorization.

1384865781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2088820.

The product of its digits is 1290240, while the sum is 51.

The square root of 1384865781 is about 37213.7848249812. The cubic root of 1384865781 is about 1114.6432612365.

The spelling of 1384865781 in words is "one billion, three hundred eighty-four million, eight hundred sixty-five thousand, seven hundred eighty-one".