1978 has 8 divisors (see below), whose sum is σ = 3168. Its totient is φ = 924.

The previous prime is 1973. The next prime is 1979. The reversal of 1978 is 8791.

1978 is nontrivially palindromic in base 5.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 12 and base 15.

It is a nialpdrome in base 13.

It is not an unprimeable number, because it can be changed into a prime (1973) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25 + ... + 67.

It is an arithmetic number, because the mean of its divisors is an integer number (396).

1978 is a deficient number, since it is larger than the sum of its proper divisors (1190).

1978 is a wasteful number, since it uses less digits than its factorization.

1978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68.

The product of its digits is 504, while the sum is 25.

The square root of 1978 is about 44.4747119159. The cubic root of 1978 is about 12.5528429616.

Subtracting from 1978 its sum of digits (25), we obtain a triangular number (1953 = T₆₂).

It can be divided in two parts, 1 and 978, that added together give a palindrome (979).

The spelling of 1978 in words is "one thousand, nine hundred seventy-eight".