1981378 has 16 divisors (see below), whose sum is σ = 3415104. Its totient is φ = 844560.

The previous prime is 1981361. The next prime is 1981393. The reversal of 1981378 is 8731891.

It is a super-3 number, since 3×1981378³ = 23335830646762866456, which contains 333 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, 4068 + ... + 4528.

It is an arithmetic number, because the mean of its divisors is an integer number (213444).

2^1981378 is an apocalyptic number.

1981378 is a deficient number, since it is larger than the sum of its proper divisors (1433726).

1981378 is a wasteful number, since it uses less digits than its factorization.

1981378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 777.

The product of its digits is 12096, while the sum is 37.

The square root of 1981378 is about 1407.6142937609. The cubic root of 1981378 is about 125.5998475257.

It can be divided in two parts, 19813 and 78, that added together give a palindrome (19891).

The spelling of 1981378 in words is "one million, nine hundred eighty-one thousand, three hundred seventy-eight".