8167749921 has 12 divisors (see below), whose sum is σ = 12204684180. Its totient is φ = 5257402080.

The previous prime is 8167749907. The next prime is 8167749923. The reversal of 8167749921 is 1299477618.

8167749921 is a `hidden beast` number, since 81 + 6 + 77 + 499 + 2 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 7005690000 + 1162059921 = 83700^2 + 34089^2 .

It is not a de Polignac number, because 8167749921 - 2¹⁴ = 8167733537 is a prime.

It is not an unprimeable number, because it can be changed into a prime (8167749923) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15646770 + ... + 15647291.

It is an arithmetic number, because the mean of its divisors is an integer number (1017057015).

Almost surely, 2^8167749921 is an apocalyptic number.

It is an amenable number.

8167749921 is a deficient number, since it is larger than the sum of its proper divisors (4036934259).

8167749921 is a wasteful number, since it uses less digits than its factorization.

8167749921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31294096 (or 31294093 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 54.

The square root of 8167749921 is about 90375.6046784750. The cubic root of 8167749921 is about 2013.8825741893.

The spelling of 8167749921 in words is "eight billion, one hundred sixty-seven million, seven hundred forty-nine thousand, nine hundred twenty-one".