8105646921 has 4 divisors (see below), whose sum is σ = 10807529232. Its totient is φ = 5403764612.

The previous prime is 8105646893. The next prime is 8105646929. The reversal of 8105646921 is 1296465018.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8105646921 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8105646929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1350941151 + ... + 1350941156.

It is an arithmetic number, because the mean of its divisors is an integer number (2701882308).

Almost surely, 2^8105646921 is an apocalyptic number.

It is an amenable number.

8105646921 is a deficient number, since it is larger than the sum of its proper divisors (2701882311).

8105646921 is a wasteful number, since it uses less digits than its factorization.

8105646921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2701882310.

The product of its (nonzero) digits is 103680, while the sum is 42.

The square root of 8105646921 is about 90031.3663175229. The cubic root of 8105646921 is about 2008.7654375131.

The spelling of 8105646921 in words is "eight billion, one hundred five million, six hundred forty-six thousand, nine hundred twenty-one".