163945890 has 64 divisors (see below), whose sum is σ = 449032320. Its totient is φ = 42534720.

The previous prime is 163945879. The next prime is 163945897. The reversal of 163945890 is 98549361.

It is a happy number.

163945890 is a `hidden beast` number, since 1 + 63 + 9 + 4 + 589 + 0 = 666.

163945890 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 (45).

It is not an unprimeable number, because it can be changed into a prime (163945897) 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, 1785 + ... + 18195.

It is an arithmetic number, because the mean of its divisors is an integer number (7016130).

Almost surely, 2^163945890 is an apocalyptic number.

163945890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 163945890, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (224516160).

163945890 is an abundant number, since it is smaller than the sum of its proper divisors (285086430).

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

163945890 is a wasteful number, since it uses less digits than its factorization.

163945890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16464 (or 16458 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 163945890 is about 12804.1356600124. The cubic root of 163945890 is about 547.3101612429.

The spelling of 163945890 in words is "one hundred sixty-three million, nine hundred forty-five thousand, eight hundred ninety".