1988167680581 has 2 divisors, whose sum is σ = 1988167680582. Its totient is φ = 1988167680580.

The previous prime is 1988167680557. The next prime is 1988167680599. The reversal of 1988167680581 is 1850867618891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1019584965025 + 968582715556 = 1009745^2 + 984166^2 .

It is a cyclic number.

It is not a de Polignac number, because 1988167680581 - 2³⁰ = 1987093938757 is a prime.

It is a super-2 number, since 2×1988167680581² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1988167680181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994083840290 + 994083840291.

It is an arithmetic number, because the mean of its divisors is an integer number (994083840291).

Almost surely, 2^{1988167680581} is an apocalyptic number.

It is an amenable number.

1988167680581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1988167680581 is an equidigital number, since it uses as much as digits as its factorization.

1988167680581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46448640, while the sum is 68.

The spelling of 1988167680581 in words is "one trillion, nine hundred eighty-eight billion, one hundred sixty-seven million, six hundred eighty thousand, five hundred eighty-one".