17989920 has 216 divisors, whose sum is σ = 68314428. Its totient is φ = 4285440.

The previous prime is 17989879. The next prime is 17989943. The reversal of 17989920 is 2998971.

It can be written as a sum of positive squares in 2 ways, for example, as 16744464 + 1245456 = 4092^2 + 1116^2 .

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 580305 + ... + 580335.

Almost surely, 2^17989920 is an apocalyptic number.

17989920 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 17989920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34157214).

17989920 is an abundant number, since it is smaller than the sum of its proper divisors (50324508).

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

17989920 is a wasteful number, since it uses less digits than its factorization.

17989920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96 (or 54 counting only the distinct ones).

The product of its (nonzero) digits is 81648, while the sum is 45.

The square root of 17989920 is about 4241.4525813688. The cubic root of 17989920 is about 262.0252097802.

The spelling of 17989920 in words is "seventeen million, nine hundred eighty-nine thousand, nine hundred twenty".