1978666867296 has 120 divisors (see below), whose sum is σ = 6650519253840. Its totient is φ = 565333385472.

The previous prime is 1978666867277. The next prime is 1978666867297. The reversal of 1978666867296 is 6927686668791.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978666867297) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 54508611 + ... + 54544898.

It is an arithmetic number, because the mean of its divisors is an integer number (55420993782).

Almost surely, 2^{1978666867296} is an apocalyptic number.

1978666867296 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1978666867296 is an abundant number, since it is smaller than the sum of its proper divisors (4671852386544).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1978666867296 is a wasteful number, since it uses less digits than its factorization.

1978666867296 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 109053538 (or 109053521 counting only the distinct ones).

The product of its digits is 3950456832, while the sum is 81.

The spelling of 1978666867296 in words is "one trillion, nine hundred seventy-eight billion, six hundred sixty-six million, eight hundred sixty-seven thousand, two hundred ninety-six".