1381881945 has 16 divisors (see below), whose sum is σ = 2211474240. Its totient is φ = 736849344.

The previous prime is 1381881931. The next prime is 1381881959. The reversal of 1381881945 is 5491881831.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1381881931) and next prime (1381881959).

It is not a de Polignac number, because 1381881945 - 2⁶ = 1381881881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1381881894 and 1381881903.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124722 + ... + 135348.

It is an arithmetic number, because the mean of its divisors is an integer number (138217140).

Almost surely, 2^1381881945 is an apocalyptic number.

1381881945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1381881945 is a deficient number, since it is larger than the sum of its proper divisors (829592295).

1381881945 is a wasteful number, since it uses less digits than its factorization.

1381881945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19304.

The product of its digits is 276480, while the sum is 48.

The square root of 1381881945 is about 37173.6727402607. The cubic root of 1381881945 is about 1113.8421476863.

The spelling of 1381881945 in words is "one billion, three hundred eighty-one million, eight hundred eighty-one thousand, nine hundred forty-five".