1978640650840 has 128 divisors (see below), whose sum is σ = 5572989993600. Its totient is φ = 616468930560.

The previous prime is 1978640650787. The next prime is 1978640650853. The reversal of 1978640650840 is 480560468791.

It is a hoax number, since the sum of its digits (58) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (58).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7028871 + ... + 7304950.

It is an arithmetic number, because the mean of its divisors is an integer number (43538984325).

Almost surely, 2^{1978640650840} is an apocalyptic number.

1978640650840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1978640650840 is an abundant number, since it is smaller than the sum of its proper divisors (3594349342760).

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

1978640650840 is a wasteful number, since it uses less digits than its factorization.

1978640650840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14333885 (or 14333881 counting only the distinct ones).

The product of its (nonzero) digits is 11612160, while the sum is 58.

The spelling of 1978640650840 in words is "one trillion, nine hundred seventy-eight billion, six hundred forty million, six hundred fifty thousand, eight hundred forty".