1943115455581 has 2 divisors, whose sum is σ = 1943115455582. Its totient is φ = 1943115455580.

The previous prime is 1943115455573. The next prime is 1943115455609. The reversal of 1943115455581 is 1855545113491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1661224543225 + 281890912356 = 1288885^2 + 530934^2 .

It is a cyclic number.

It is not a de Polignac number, because 1943115455581 - 2³ = 1943115455573 is a prime.

It is a super-2 number, since 2×1943115455581² (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 (1943115455881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 971557727790 + 971557727791.

It is an arithmetic number, because the mean of its divisors is an integer number (971557727791).

Almost surely, 2^{1943115455581} is an apocalyptic number.

It is an amenable number.

1943115455581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1943115455581 is an equidigital number, since it uses as much as digits as its factorization.

1943115455581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160000, while the sum is 52.

The spelling of 1943115455581 in words is "one trillion, nine hundred forty-three billion, one hundred fifteen million, four hundred fifty-five thousand, five hundred eighty-one".