163581000 has 128 divisors (see below), whose sum is σ = 556882560. Its totient is φ = 39648000.

The previous prime is 163580993. The next prime is 163581007. The reversal of 163581000 is 185361.

It is an interprime number because it is at equal distance from previous prime (163580993) and next prime (163581007).

It is a super-2 number, since 2×163581000² = 53517487122000000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (163581007) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30522 + ... + 35478.

It is an arithmetic number, because the mean of its divisors is an integer number (4350645).

Almost surely, 2^163581000 is an apocalyptic number.

163581000 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 163581000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (278441280).

163581000 is an abundant number, since it is smaller than the sum of its proper divisors (393301560).

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

163581000 is a wasteful number, since it uses less digits than its factorization.

163581000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4992 (or 4978 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 24.

The square root of 163581000 is about 12789.8788109974. The cubic root of 163581000 is about 546.9038150803.

The spelling of 163581000 in words is "one hundred sixty-three million, five hundred eighty-one thousand".