1939978 has 4 divisors (see below), whose sum is σ = 2909970. Its totient is φ = 969988.

The previous prime is 1939969. The next prime is 1939999. The reversal of 1939978 is 8799391.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1868689 + 71289 = 1367^2 + 267^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 484993 + ... + 484996.

2^1939978 is an apocalyptic number.

1939978 is a deficient number, since it is larger than the sum of its proper divisors (969992).

1939978 is an equidigital number, since it uses as much as digits as its factorization.

1939978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 969991.

The product of its digits is 122472, while the sum is 46.

The square root of 1939978 is about 1392.8309301563. The cubic root of 1939978 is about 124.7188989983.

The spelling of 1939978 in words is "one million, nine hundred thirty-nine thousand, nine hundred seventy-eight".