161853653597 has 4 divisors (see below), whose sum is σ = 162620732736. Its totient is φ = 161086574460.

The previous prime is 161853653573. The next prime is 161853653609. The reversal of 161853653597 is 795356358161.

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, and also an emirpimes, since its reverse is a distinct semiprime: 795356358161 = 307 ⋅2590737323.

It is a cyclic number.

It is not a de Polignac number, because 161853653597 - 2¹² = 161853649501 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 (161853653527) 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, 383539253 + ... + 383539674.

It is an arithmetic number, because the mean of its divisors is an integer number (40655183184).

Almost surely, 2^161853653597 is an apocalyptic number.

It is an amenable number.

161853653597 is a deficient number, since it is larger than the sum of its proper divisors (767079139).

161853653597 is an equidigital number, since it uses as much as digits as its factorization.

161853653597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 767079138.

The product of its digits is 20412000, while the sum is 59.

The spelling of 161853653597 in words is "one hundred sixty-one billion, eight hundred fifty-three million, six hundred fifty-three thousand, five hundred ninety-seven".