8649816981 has 24 divisors (see below), whose sum is σ = 12512755296. Its totient is φ = 5312623680.

The previous prime is 8649816941. The next prime is 8649817021. The reversal of 8649816981 is 1896189468.

It is an interprime number because it is at equal distance from previous prime (8649816941) and next prime (8649817021).

It is not a de Polignac number, because 8649816981 - 2⁷ = 8649816853 is a prime.

It is a super-2 number, since 2×8649816981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8649816941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 248851 + ... + 281471.

It is an arithmetic number, because the mean of its divisors is an integer number (521364804).

Almost surely, 2^8649816981 is an apocalyptic number.

It is an amenable number.

8649816981 is a deficient number, since it is larger than the sum of its proper divisors (3862938315).

8649816981 is a wasteful number, since it uses less digits than its factorization.

8649816981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33173 (or 33160 counting only the distinct ones).

The product of its digits is 5971968, while the sum is 60.

The square root of 8649816981 is about 93004.3922672472. The cubic root of 8649816981 is about 2052.7480085829.

The spelling of 8649816981 in words is "eight billion, six hundred forty-nine million, eight hundred sixteen thousand, nine hundred eighty-one".