161640397579 has 8 divisors (see below), whose sum is σ = 168672545280. Its totient is φ = 154608608616.

The previous prime is 161640397531. The next prime is 161640397601. The reversal of 161640397579 is 975793046161.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 161640397579 - 2¹¹ = 161640395531 is a prime.

It is a super-2 number, since 2×161640397579² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161640347579) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1269544 + ... + 1391050.

It is an arithmetic number, because the mean of its divisors is an integer number (21084068160).

Almost surely, 2^161640397579 is an apocalyptic number.

161640397579 is a deficient number, since it is larger than the sum of its proper divisors (7032147701).

161640397579 is a wasteful number, since it uses less digits than its factorization.

161640397579 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 179369.

The product of its (nonzero) digits is 8573040, while the sum is 58.

The spelling of 161640397579 in words is "one hundred sixty-one billion, six hundred forty million, three hundred ninety-seven thousand, five hundred seventy-nine".