8188971649 has 4 divisors (see below), whose sum is σ = 8210023380. Its totient is φ = 8167919920.

The previous prime is 8188971631. The next prime is 8188971667. The reversal of 8188971649 is 9461798818.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (8188971631) and next prime (8188971667).

It can be written as a sum of positive squares in 2 ways, for example, as 5616453249 + 2572518400 = 74943^2 + 50720^2 .

It is a cyclic number.

It is not a de Polignac number, because 8188971649 - 2⁷ = 8188971521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8188971629) 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, 10525282 + ... + 10526059.

It is an arithmetic number, because the mean of its divisors is an integer number (2052505845).

Almost surely, 2^8188971649 is an apocalyptic number.

It is an amenable number.

8188971649 is a deficient number, since it is larger than the sum of its proper divisors (21051731).

8188971649 is a wasteful number, since it uses less digits than its factorization.

8188971649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21051730.

The product of its digits is 6967296, while the sum is 61.

The square root of 8188971649 is about 90492.9370116806. The cubic root of 8188971649 is about 2015.6252453639.

The spelling of 8188971649 in words is "eight billion, one hundred eighty-eight million, nine hundred seventy-one thousand, six hundred forty-nine".