161581138022 has 4 divisors (see below), whose sum is σ = 242371707036. Its totient is φ = 80790569010.

The previous prime is 161581138013. The next prime is 161581138027. The reversal of 161581138022 is 220831185161.

161581138022 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 220831185161 = 163 ⋅1354792547.

It is a super-2 number, since 2×161581138022² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161581138027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40395284504 + ... + 40395284507.

It is an arithmetic number, because the mean of its divisors is an integer number (60592926759).

Almost surely, 2^161581138022 is an apocalyptic number.

161581138022 is a deficient number, since it is larger than the sum of its proper divisors (80790569014).

161581138022 is an equidigital number, since it uses as much as digits as its factorization.

161581138022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80790569013.

The product of its (nonzero) digits is 23040, while the sum is 38.

The spelling of 161581138022 in words is "one hundred sixty-one billion, five hundred eighty-one million, one hundred thirty-eight thousand, twenty-two".