19809216 has 168 divisors, whose sum is σ = 68945760. Its totient is φ = 5326848.

The previous prime is 19809211. The next prime is 19809221. The reversal of 19809216 is 61290891.

It is an interprime number because it is at equal distance from previous prime (19809211) and next prime (19809221).

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19809211) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1165240 + ... + 1165256.

Almost surely, 2^19809216 is an apocalyptic number.

19809216 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 19809216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34472880).

19809216 is an abundant number, since it is smaller than the sum of its proper divisors (49136544).

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

19809216 is an equidigital number, since it uses as much as digits as its factorization.

19809216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76 (or 29 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 19809216 is about 4450.7545427714. The cubic root of 19809216 is about 270.5758901370.

The spelling of 19809216 in words is "nineteen million, eight hundred nine thousand, two hundred sixteen".