1781987268820 has 48 divisors (see below), whose sum is σ = 4259865230208. Its totient is φ = 619821656960.

The previous prime is 1781987268811. The next prime is 1781987268851. The reversal of 1781987268820 is 288627891871.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 176080639 + ... + 176090758.

It is an arithmetic number, because the mean of its divisors is an integer number (88747192296).

Almost surely, 2^{1781987268820} is an apocalyptic number.

1781987268820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1781987268820 is an abundant number, since it is smaller than the sum of its proper divisors (2477877961388).

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

1781987268820 is a wasteful number, since it uses less digits than its factorization.

1781987268820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352171440 (or 352171438 counting only the distinct ones).

The product of its (nonzero) digits is 43352064, while the sum is 67.

The spelling of 1781987268820 in words is "one trillion, seven hundred eighty-one billion, nine hundred eighty-seven million, two hundred sixty-eight thousand, eight hundred twenty".