161761619 has 4 divisors (see below), whose sum is σ = 162833040. Its totient is φ = 160690200.

The previous prime is 161761609. The next prime is 161761661. The reversal of 161761619 is 916167161.

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 161761619 - 2²⁴ = 144984403 is a prime.

It is a super-3 number, since 3×161761619³ (a number of 26 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 (161761609) 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, 535484 + ... + 535785.

It is an arithmetic number, because the mean of its divisors is an integer number (40708260).

Almost surely, 2^161761619 is an apocalyptic number.

161761619 is a deficient number, since it is larger than the sum of its proper divisors (1071421).

161761619 is a wasteful number, since it uses less digits than its factorization.

161761619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071420.

The product of its digits is 13608, while the sum is 38.

The square root of 161761619 is about 12718.5541237988. The cubic root of 161761619 is about 544.8686595382.

It can be divided in two parts, 1617 and 61619, that added together give a palindrome (63236).

The spelling of 161761619 in words is "one hundred sixty-one million, seven hundred sixty-one thousand, six hundred nineteen".