43487370581 has 4 divisors (see below), whose sum is σ = 43493373612. Its totient is φ = 43481367552.

The previous prime is 43487370569. The next prime is 43487370593. The reversal of 43487370581 is 18507378434.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (43487370569) and next prime (43487370593).

It can be written as a sum of positive squares in 2 ways, for example, as 30133488100 + 13353882481 = 173590^2 + 115559^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-43487370581 is a prime.

It is a super-2 number, since 2×43487370581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43487370781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2990636 + ... + 3005141.

It is an arithmetic number, because the mean of its divisors is an integer number (10873343403).

Almost surely, 2^43487370581 is an apocalyptic number.

It is an amenable number.

43487370581 is a deficient number, since it is larger than the sum of its proper divisors (6003031).

43487370581 is an equidigital number, since it uses as much as digits as its factorization.

43487370581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6003030.

The product of its (nonzero) digits is 2257920, while the sum is 50.

The spelling of 43487370581 in words is "forty-three billion, four hundred eighty-seven million, three hundred seventy thousand, five hundred eighty-one".