161861390929 has 32 divisors (see below), whose sum is σ = 188041847040. Its totient is φ = 136466208000.

The previous prime is 161861390893. The next prime is 161861390939. The reversal of 161861390929 is 929093168161.

161861390929 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 161861390929 - 2⁹ = 161861390417 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161861390929.

It is not an unprimeable number, because it can be changed into a prime (161861390939) 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 in 31 ways as a sum of consecutive naturals, for example, 105721894 + ... + 105723424.

It is an arithmetic number, because the mean of its divisors is an integer number (5876307720).

Almost surely, 2^161861390929 is an apocalyptic number.

It is an amenable number.

161861390929 is a deficient number, since it is larger than the sum of its proper divisors (26180456111).

161861390929 is a wasteful number, since it uses less digits than its factorization.

161861390929 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2521.

The product of its (nonzero) digits is 1259712, while the sum is 55.

The spelling of 161861390929 in words is "one hundred sixty-one billion, eight hundred sixty-one million, three hundred ninety thousand, nine hundred twenty-nine".