1978795994 has 16 divisors (see below), whose sum is σ = 3400102656. Its totient is φ = 846085200.

The previous prime is 1978795993. The next prime is 1978796009. The reversal of 1978795994 is 4995978791.

It is not an unprimeable number, because it can be changed into a prime (1978795991) 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, 157937 + ... + 170004.

It is an arithmetic number, because the mean of its divisors is an integer number (212506416).

Almost surely, 2^1978795994 is an apocalyptic number.

1978795994 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

1978795994 is a deficient number, since it is larger than the sum of its proper divisors (1421306662).

1978795994 is a wasteful number, since it uses less digits than its factorization.

1978795994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328381.

The product of its digits is 51438240, while the sum is 68.

The square root of 1978795994 is about 44483.6598539284. The cubic root of 1978795994 is about 1255.4526589437.

The spelling of 1978795994 in words is "one billion, nine hundred seventy-eight million, seven hundred ninety-five thousand, nine hundred ninety-four".