8520666381 has 12 divisors (see below), whose sum is σ = 12369479200. Its totient is φ = 5651898120.

The previous prime is 8520666377. The next prime is 8520666403. The reversal of 8520666381 is 1836660258.

It is not a de Polignac number, because 8520666381 - 2² = 8520666377 is a prime.

It is a super-2 number, since 2×8520666381² (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 (8520666311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2376955 + ... + 2380536.

Almost surely, 2^8520666381 is an apocalyptic number.

It is an amenable number.

8520666381 is a deficient number, since it is larger than the sum of its proper divisors (3848812819).

8520666381 is a wasteful number, since it uses less digits than its factorization.

8520666381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4757696 (or 4757693 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 8520666381 is about 92307.4557172930. The cubic root of 8520666381 is about 2042.4801934691.

The spelling of 8520666381 in words is "eight billion, five hundred twenty million, six hundred sixty-six thousand, three hundred eighty-one".