8161192621 has 4 divisors (see below), whose sum is σ = 8166675100. Its totient is φ = 8155710144.

The previous prime is 8161192597. The next prime is 8161192667. The reversal of 8161192621 is 1262911618.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1262911618 = 2 ⋅631455809.

It can be written as a sum of positive squares in 2 ways, for example, as 1016716996 + 7144475625 = 31886^2 + 84525^2 .

It is a cyclic number.

It is not a de Polignac number, because 8161192621 - 2²⁹ = 7624321709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8161192681) 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, 2739006 + ... + 2741983.

It is an arithmetic number, because the mean of its divisors is an integer number (2041668775).

Almost surely, 2^8161192621 is an apocalyptic number.

It is an amenable number.

8161192621 is a deficient number, since it is larger than the sum of its proper divisors (5482479).

8161192621 is a wasteful number, since it uses less digits than its factorization.

8161192621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5482478.

The product of its digits is 10368, while the sum is 37.

The square root of 8161192621 is about 90339.3193520961. The cubic root of 8161192621 is about 2013.3434959912.

The spelling of 8161192621 in words is "eight billion, one hundred sixty-one million, one hundred ninety-two thousand, six hundred twenty-one".