8665403981 has 8 divisors (see below), whose sum is σ = 9344311704. Its totient is φ = 7988258880.

The previous prime is 8665403977. The next prime is 8665403987. The reversal of 8665403981 is 1893045668.

It can be written as a sum of positive squares in 4 ways, for example, as 1332907081 + 7332496900 = 36509^2 + 85630^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 8665403981 - 2² = 8665403977 is a prime.

It is a super-2 number, since 2×8665403981² (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 (8665403987) 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, 430430 + ... + 450111.

It is an arithmetic number, because the mean of its divisors is an integer number (1168038963).

Almost surely, 2^8665403981 is an apocalyptic number.

It is an amenable number.

8665403981 is a deficient number, since it is larger than the sum of its proper divisors (678907723).

8665403981 is a wasteful number, since it uses less digits than its factorization.

8665403981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 881311.

The product of its (nonzero) digits is 1244160, while the sum is 50.

The square root of 8665403981 is about 93088.1516681903. The cubic root of 8665403981 is about 2053.9802883494.

The spelling of 8665403981 in words is "eight billion, six hundred sixty-five million, four hundred three thousand, nine hundred eighty-one".