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16920 = 2332547

16920 has 48 divisors (see below), whose sum is σ = 56160. Its totient is φ = 4416.

The previous prime is 16903. The next prime is 16921. The reversal of 16920 is 2961.

Adding to 16920 its reverse (2961), we get a square (19881 = 1412).

16920 = T61 + T62 + ... + T68.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nialpdrome in base 12.

It is a junction number, because it is equal to n+sod(n) for n = 16893 and 16902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16921) by changing a digit.

16920 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 337 + ... + 383.

It is an arithmetic number, because the mean of its divisors is an integer number (1170).

216920 is an apocalyptic number.

16920 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 16920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28080).

16920 is an abundant number, since it is smaller than the sum of its proper divisors (39240).

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

16920 is a wasteful number, since it uses less digits than its factorization.

16920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 18.

The square root of 16920 is about 130.0769003321. The cubic root of 16920 is about 25.6724186430.

The spelling of 16920 in words is "sixteen thousand, nine hundred twenty".