1978489292794 has 20 divisors (see below), whose sum is σ = 3462150263994. Its totient is φ = 847923980568.

The previous prime is 1978489292713. The next prime is 1978489292861. The reversal of 1978489292794 is 4972929848791.

It can be written as a sum of positive squares in only one way, i.e., 1847188146769 + 131301146025 = 1359113^2 + 362355^2 .

It is a super-3 number, since 3×1978489292794³ (a number of 38 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 206001997 + ... + 206011600.

Almost surely, 2^{1978489292794} is an apocalyptic number.

1978489292794 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

1978489292794 is a deficient number, since it is larger than the sum of its proper divisors (1483660971200).

1978489292794 is an frugal number, since it uses more digits than its factorization.

1978489292794 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 412013627 (or 412013606 counting only the distinct ones).

The product of its digits is 1316818944, while the sum is 79.

The spelling of 1978489292794 in words is "one trillion, nine hundred seventy-eight billion, four hundred eighty-nine million, two hundred ninety-two thousand, seven hundred ninety-four".