1981340544456 has 224 divisors, whose sum is σ = 6855352311360. Its totient is φ = 522551212416.

The previous prime is 1981340544433. The next prime is 1981340544457. The reversal of 1981340544456 is 6544450431891.

1981340544456 is a `hidden beast` number, since 1 + 9 + 8 + 1 + 3 + 40 + 544 + 4 + 56 = 666.

It is a super-3 number, since 3×1981340544456³ (a number of 38 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (1981340544457) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 1335970 + ... + 2397393.

It is an arithmetic number, because the mean of its divisors is an integer number (30604251390).

Almost surely, 2^{1981340544456} is an apocalyptic number.

It is an amenable number.

1981340544456 is an abundant number, since it is smaller than the sum of its proper divisors (4874011766904).

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

1981340544456 is a wasteful number, since it uses less digits than its factorization.

1981340544456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3733407 (or 3733388 counting only the distinct ones).

The product of its (nonzero) digits is 8294400, while the sum is 54.

The spelling of 1981340544456 in words is "one trillion, nine hundred eighty-one billion, three hundred forty million, five hundred forty-four thousand, four hundred fifty-six".