1381978 has 16 divisors (see below), whose sum is σ = 2330496. Its totient is φ = 609840.

The previous prime is 1381973. The next prime is 1381979. The reversal of 1381978 is 8791831.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1381973) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 558 + ... + 1753.

It is an arithmetic number, because the mean of its divisors is an integer number (145656).

2^1381978 is an apocalyptic number.

1381978 is a deficient number, since it is larger than the sum of its proper divisors (948518).

1381978 is a wasteful number, since it uses less digits than its factorization.

1381978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2349.

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

The square root of 1381978 is about 1175.5756036938. The cubic root of 1381978 is about 111.3867954915.

It can be divided in two parts, 138 and 1978, that added together give a square (2116 = 46²).

The spelling of 1381978 in words is "one million, three hundred eighty-one thousand, nine hundred seventy-eight".