161959280640 has 256 divisors, whose sum is σ = 523189497600. Its totient is φ = 42778755072.

The previous prime is 161959280629. The next prime is 161959280663. The reversal of 161959280640 is 46082959161.

It is a tau number, because it is divible by the number of its divisors (256).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53574169 + ... + 53577191.

It is an arithmetic number, because the mean of its divisors is an integer number (2043708975).

Almost surely, 2^161959280640 is an apocalyptic number.

161959280640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161959280640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261594748800).

161959280640 is an abundant number, since it is smaller than the sum of its proper divisors (361230216960).

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

161959280640 is an equidigital number, since it uses as much as digits as its factorization.

161959280640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3170 (or 3142 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 51.

The spelling of 161959280640 in words is "one hundred sixty-one billion, nine hundred fifty-nine million, two hundred eighty thousand, six hundred forty".