161357432531 has 4 divisors (see below), whose sum is σ = 169849929000. Its totient is φ = 152864936064.

The previous prime is 161357432449. The next prime is 161357432591. The reversal of 161357432531 is 135234753161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 135234753161 = 97 ⋅1394172713.

It is a cyclic number.

It is not a de Polignac number, because 161357432531 - 2¹⁴ = 161357416147 is a prime.

It is a super-3 number, since 3×161357432531³ (a number of 35 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161357432591) 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, 4246248206 + ... + 4246248243.

It is an arithmetic number, because the mean of its divisors is an integer number (42462482250).

Almost surely, 2^161357432531 is an apocalyptic number.

161357432531 is a deficient number, since it is larger than the sum of its proper divisors (8492496469).

161357432531 is an equidigital number, since it uses as much as digits as its factorization.

161357432531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8492496468.

The product of its digits is 226800, while the sum is 41.

The spelling of 161357432531 in words is "one hundred sixty-one billion, three hundred fifty-seven million, four hundred thirty-two thousand, five hundred thirty-one".