161081403681 has 16 divisors (see below), whose sum is σ = 234335844288. Its totient is φ = 97610251200.

The previous prime is 161081403673. The next prime is 161081403709. The reversal of 161081403681 is 186304180161.

It is not a de Polignac number, because 161081403681 - 2³ = 161081403673 is a prime.

It is a super-2 number, since 2×161081403681² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (161081403671) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148710 + ... + 586751.

It is an arithmetic number, because the mean of its divisors is an integer number (14645990268).

Almost surely, 2^161081403681 is an apocalyptic number.

161081403681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161081403681 is a deficient number, since it is larger than the sum of its proper divisors (73254440607).

161081403681 is a wasteful number, since it uses less digits than its factorization.

161081403681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 742112.

The product of its (nonzero) digits is 27648, while the sum is 39.

The spelling of 161081403681 in words is "one hundred sixty-one billion, eighty-one million, four hundred three thousand, six hundred eighty-one".