43115363581 has 2 divisors, whose sum is σ = 43115363582. Its totient is φ = 43115363580.

The previous prime is 43115363537. The next prime is 43115363593. The reversal of 43115363581 is 18536351134.

43115363581 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 35342120025 + 7773243556 = 187995^2 + 88166^2 .

It is a cyclic number.

It is not a de Polignac number, because 43115363581 - 2¹⁹ = 43114839293 is a prime.

It is a super-2 number, since 2×43115363581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43115363381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21557681790 + 21557681791.

It is an arithmetic number, because the mean of its divisors is an integer number (21557681791).

Almost surely, 2^43115363581 is an apocalyptic number.

It is an amenable number.

43115363581 is a deficient number, since it is larger than the sum of its proper divisors (1).

43115363581 is an equidigital number, since it uses as much as digits as its factorization.

43115363581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 129600, while the sum is 40.

The spelling of 43115363581 in words is "forty-three billion, one hundred fifteen million, three hundred sixty-three thousand, five hundred eighty-one".