161528782821 has 16 divisors (see below), whose sum is σ = 246523110528. Its totient is φ = 92158156800.

The previous prime is 161528782817. The next prime is 161528782829. The reversal of 161528782821 is 128287825161.

It is not a de Polignac number, because 161528782821 - 2² = 161528782817 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161528782829) 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, 5986420 + ... + 6013341.

It is an arithmetic number, because the mean of its divisors is an integer number (15407694408).

Almost surely, 2^161528782821 is an apocalyptic number.

It is an amenable number.

161528782821 is a deficient number, since it is larger than the sum of its proper divisors (84994327707).

161528782821 is a wasteful number, since it uses less digits than its factorization.

161528782821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12000412.

The product of its digits is 860160, while the sum is 51.

The spelling of 161528782821 in words is "one hundred sixty-one billion, five hundred twenty-eight million, seven hundred eighty-two thousand, eight hundred twenty-one".