161819616583 has 4 divisors (see below), whose sum is σ = 163867966240. Its totient is φ = 159771266928.

The previous prime is 161819616577. The next prime is 161819616599. The reversal of 161819616583 is 385616918161.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-161819616583 is a prime.

It is a super-2 number, since 2×161819616583² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161819616083) 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, 1024174710 + ... + 1024174867.

It is an arithmetic number, because the mean of its divisors is an integer number (40966991560).

Almost surely, 2^161819616583 is an apocalyptic number.

161819616583 is a deficient number, since it is larger than the sum of its proper divisors (2048349657).

161819616583 is an equidigital number, since it uses as much as digits as its factorization.

161819616583 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2048349656.

The product of its digits is 1866240, while the sum is 55.

The spelling of 161819616583 in words is "one hundred sixty-one billion, eight hundred nineteen million, six hundred sixteen thousand, five hundred eighty-three".