161949504020 has 24 divisors (see below), whose sum is σ = 340591928544. Its totient is φ = 64684950176.

The previous prime is 161949503983. The next prime is 161949504029. The reversal of 161949504020 is 20405949161.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161949504029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5914214 + ... + 5941533.

It is an arithmetic number, because the mean of its divisors is an integer number (14191330356).

Almost surely, 2^161949504020 is an apocalyptic number.

161949504020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161949504020 is an abundant number, since it is smaller than the sum of its proper divisors (178642424524).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161949504020 is a wasteful number, since it uses less digits than its factorization.

161949504020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11856439 (or 11856437 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 41.

The spelling of 161949504020 in words is "one hundred sixty-one billion, nine hundred forty-nine million, five hundred four thousand, twenty".