1981463378977 has 16 divisors (see below), whose sum is σ = 2110443627600. Its totient is φ = 1857000463360.

The previous prime is 1981463378963. The next prime is 1981463378981. The reversal of 1981463378977 is 7798733641891.

It can be written as a sum of positive squares in 8 ways, for example, as 56873187361 + 1924590191616 = 238481^2 + 1387296^2 .

It is a cyclic number.

It is not a de Polignac number, because 1981463378977 - 2²³ = 1981454990369 is a prime.

It is a super-3 number, since 3×1981463378977³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981463388977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3995452 + ... + 4463917.

It is an arithmetic number, because the mean of its divisors is an integer number (131902726725).

Almost surely, 2^{1981463378977} is an apocalyptic number.

It is an amenable number.

1981463378977 is a deficient number, since it is larger than the sum of its proper divisors (128980248623).

1981463378977 is a wasteful number, since it uses less digits than its factorization.

1981463378977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8459636.

The product of its digits is 384072192, while the sum is 73.

The spelling of 1981463378977 in words is "one trillion, nine hundred eighty-one billion, four hundred sixty-three million, three hundred seventy-eight thousand, nine hundred seventy-seven".