1043691581 has 2 divisors, whose sum is σ = 1043691582. Its totient is φ = 1043691580.

The previous prime is 1043691577. The next prime is 1043691587. The reversal of 1043691581 is 1851963401.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1015696900 + 27994681 = 31870^2 + 5291^2 .

It is an emirp because it is prime and its reverse (1851963401) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1043691581 - 2² = 1043691577 is a prime.

It is a super-2 number, since 2×1043691581² = 2178584232500559122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1043691587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 521845790 + 521845791.

It is an arithmetic number, because the mean of its divisors is an integer number (521845791).

Almost surely, 2^1043691581 is an apocalyptic number.

It is an amenable number.

1043691581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1043691581 is an equidigital number, since it uses as much as digits as its factorization.

1043691581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 1043691581 is about 32306.2158260605. The cubic root of 1043691581 is about 1014.3567574604.

The spelling of 1043691581 in words is "one billion, forty-three million, six hundred ninety-one thousand, five hundred eighty-one".