161810203606 has 4 divisors (see below), whose sum is σ = 242715305412. Its totient is φ = 80905101802.

The previous prime is 161810203601. The next prime is 161810203609. The reversal of 161810203606 is 606302018161.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161810203601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40452550900 + ... + 40452550903.

It is an arithmetic number, because the mean of its divisors is an integer number (60678826353).

Almost surely, 2^161810203606 is an apocalyptic number.

161810203606 is a deficient number, since it is larger than the sum of its proper divisors (80905101806).

161810203606 is an equidigital number, since it uses as much as digits as its factorization.

161810203606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80905101805.

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 161810203606 in words is "one hundred sixty-one billion, eight hundred ten million, two hundred three thousand, six hundred six".