161660540203 has 4 divisors (see below), whose sum is σ = 162011214288. Its totient is φ = 161309866120.

The previous prime is 161660540087. The next prime is 161660540257. The reversal of 161660540203 is 302045066161.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 161660540203 - 2³⁷ = 24221586731 is a prime.

It is a super-2 number, since 2×161660540203² (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 (161660540003) 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, 175336351 + ... + 175337272.

It is an arithmetic number, because the mean of its divisors is an integer number (40502803572).

Almost surely, 2^161660540203 is an apocalyptic number.

161660540203 is a deficient number, since it is larger than the sum of its proper divisors (350674085).

161660540203 is an equidigital number, since it uses as much as digits as its factorization.

161660540203 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 350674084.

The product of its (nonzero) digits is 25920, while the sum is 34.

The spelling of 161660540203 in words is "one hundred sixty-one billion, six hundred sixty million, five hundred forty thousand, two hundred three".