8601991381 has 4 divisors (see below), whose sum is σ = 9107990892. Its totient is φ = 8095991872.

The previous prime is 8601991379. The next prime is 8601991403. The reversal of 8601991381 is 1831991068.

It is a happy number.

8601991381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6055174225 + 2546817156 = 77815^2 + 50466^2 .

It is not a de Polignac number, because 8601991381 - 2¹ = 8601991379 is a prime.

It is a super-2 number, since 2×8601991381² (a number of 21 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 (8601991301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 252999730 + ... + 252999763.

It is an arithmetic number, because the mean of its divisors is an integer number (2276997723).

Almost surely, 2^8601991381 is an apocalyptic number.

It is an amenable number.

8601991381 is a deficient number, since it is larger than the sum of its proper divisors (505999511).

8601991381 is a wasteful number, since it uses less digits than its factorization.

8601991381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505999510.

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 8601991381 is about 92746.9211402729. The cubic root of 8601991381 is about 2048.9577395475.

The spelling of 8601991381 in words is "eight billion, six hundred one million, nine hundred ninety-one thousand, three hundred eighty-one".