161921457024 has 128 divisors (see below), whose sum is σ = 439147699200. Its totient is φ = 52850466816.

The previous prime is 161921456999. The next prime is 161921457097. The reversal of 161921457024 is 420754129161.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 3579057 + ... + 3624015.

It is an arithmetic number, because the mean of its divisors is an integer number (3430841400).

Almost surely, 2^161921457024 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161921457024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (219573849600).

161921457024 is an abundant number, since it is smaller than the sum of its proper divisors (277226242176).

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

161921457024 is a wasteful number, since it uses less digits than its factorization.

161921457024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45172 (or 45160 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The spelling of 161921457024 in words is "one hundred sixty-one billion, nine hundred twenty-one million, four hundred fifty-seven thousand, twenty-four".