161591189810 has 8 divisors (see below), whose sum is σ = 290864141676. Its totient is φ = 64636475920.

The previous prime is 161591189803. The next prime is 161591189831. The reversal of 161591189810 is 18981195161.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 153028833721 + 8562356089 = 391189^2 + 92533^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×161591189810² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8079559481 + ... + 8079559500.

Almost surely, 2^161591189810 is an apocalyptic number.

161591189810 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161591189810 is a deficient number, since it is larger than the sum of its proper divisors (129272951866).

161591189810 is a wasteful number, since it uses less digits than its factorization.

161591189810 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16159118988.

The product of its (nonzero) digits is 155520, while the sum is 50.

The spelling of 161591189810 in words is "one hundred sixty-one billion, five hundred ninety-one million, one hundred eighty-nine thousand, eight hundred ten".