9815939081 has 8 divisors (see below), whose sum is σ = 10588845960. Its totient is φ = 9045580032.

The previous prime is 9815939071. The next prime is 9815939131. The reversal of 9815939081 is 1809395189.

It can be written as a sum of positive squares in 4 ways, for example, as 1990944400 + 7824994681 = 44620^2 + 88459^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9815939081 is a prime.

It is a super-2 number, since 2×9815939081² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9815939071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 628946 + ... + 644363.

It is an arithmetic number, because the mean of its divisors is an integer number (1323605745).

Almost surely, 2^9815939081 is an apocalyptic number.

It is an amenable number.

9815939081 is a deficient number, since it is larger than the sum of its proper divisors (772906879).

9815939081 is a wasteful number, since it uses less digits than its factorization.

9815939081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273915.

The product of its (nonzero) digits is 699840, while the sum is 53.

The square root of 9815939081 is about 99075.4211749816. The cubic root of 9815939081 is about 2141.1345107479.

The spelling of 9815939081 in words is "nine billion, eight hundred fifteen million, nine hundred thirty-nine thousand, eighty-one".