849311581 has 2 divisors, whose sum is σ = 849311582. Its totient is φ = 849311580.

The previous prime is 849311569. The next prime is 849311657. The reversal of 849311581 is 185113948.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 569585956 + 279725625 = 23866^2 + 16725^2 .

It is a cyclic number.

It is not a de Polignac number, because 849311581 - 2⁷ = 849311453 is a prime.

It is a super-2 number, since 2×849311581² = 1442660323241439122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (849311531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 424655790 + 424655791.

It is an arithmetic number, because the mean of its divisors is an integer number (424655791).

Almost surely, 2^849311581 is an apocalyptic number.

It is an amenable number.

849311581 is a deficient number, since it is larger than the sum of its proper divisors (1).

849311581 is an equidigital number, since it uses as much as digits as its factorization.

849311581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 34560, while the sum is 40.

The square root of 849311581 is about 29142.9507943173. The cubic root of 849311581 is about 947.0124357809.

The spelling of 849311581 in words is "eight hundred forty-nine million, three hundred eleven thousand, five hundred eighty-one".