19221616 has 40 divisors (see below), whose sum is σ = 39975120. Its totient is φ = 8925696.

The previous prime is 19221607. The next prime is 19221619. The reversal of 19221616 is 61612291.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19221619) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15516 + ... + 16708.

It is an arithmetic number, because the mean of its divisors is an integer number (999378).

Almost surely, 2^19221616 is an apocalyptic number.

19221616 is a gapful number since it is divisible by the number (16) 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 19221616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19987560).

19221616 is an abundant number, since it is smaller than the sum of its proper divisors (20753504).

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

19221616 is a wasteful number, since it uses less digits than its factorization.

19221616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1273 (or 1267 counting only the distinct ones).

The product of its digits is 1296, while the sum is 28.

The square root of 19221616 is about 4384.2463434438. The cubic root of 19221616 is about 267.8736316690.

It can be divided in two parts, 19 and 221616, that multiplied together give a square (4210704 = 2052²).

The spelling of 19221616 in words is "nineteen million, two hundred twenty-one thousand, six hundred sixteen".