161801580 has 192 divisors, whose sum is σ = 507523968. Its totient is φ = 38338560.

The previous prime is 161801569. The next prime is 161801581. The reversal of 161801580 is 85108161.

It is a happy number.

161801580 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (161801581) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2216424 + ... + 2216496.

It is an arithmetic number, because the mean of its divisors is an integer number (2643354).

Almost surely, 2^161801580 is an apocalyptic number.

161801580 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 161801580, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253761984).

161801580 is an abundant number, since it is smaller than the sum of its proper divisors (345722388).

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

161801580 is a wasteful number, since it uses less digits than its factorization.

161801580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 194 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 30.

The square root of 161801580 is about 12720.1249993858. The cubic root of 161801580 is about 544.9135232991.

The spelling of 161801580 in words is "one hundred sixty-one million, eight hundred one thousand, five hundred eighty".