163661380 has 48 divisors (see below), whose sum is σ = 366629760. Its totient is φ = 61152768.

The previous prime is 163661357. The next prime is 163661387. The reversal of 163661380 is 83166361.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is not an unprimeable number, because it can be changed into a prime (163661387) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45529 + ... + 48991.

It is an arithmetic number, because the mean of its divisors is an integer number (7638120).

Almost surely, 2^163661380 is an apocalyptic number.

163661380 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 163661380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183314880).

163661380 is an abundant number, since it is smaller than the sum of its proper divisors (202968380).

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

163661380 is a wasteful number, since it uses less digits than its factorization.

163661380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3628 (or 3626 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 163661380 is about 12793.0207535203. The cubic root of 163661380 is about 546.9933791297.

The spelling of 163661380 in words is "one hundred sixty-three million, six hundred sixty-one thousand, three hundred eighty".