19221920 has 48 divisors (see below), whose sum is σ = 47809440. Its totient is φ = 7282944.

The previous prime is 19221913. The next prime is 19221941. The reversal of 19221920 is 2912291.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 19221920.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122 + ... + 6201.

It is an arithmetic number, because the mean of its divisors is an integer number (996030).

Almost surely, 2^19221920 is an apocalyptic number.

19221920 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 19221920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23904720).

19221920 is an abundant number, since it is smaller than the sum of its proper divisors (28587520).

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

19221920 is a wasteful number, since it uses less digits than its factorization.

19221920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6357 (or 6349 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 26.

The square root of 19221920 is about 4384.2810128914. The cubic root of 19221920 is about 267.8750438491.

Multiplying 19221920 by its sum of digits (26), we get a triangular number (499769920 = T₃₁₆₁₅).

The spelling of 19221920 in words is "nineteen million, two hundred twenty-one thousand, nine hundred twenty".