1916621808 has 80 divisors (see below), whose sum is σ = 5244247680. Its totient is φ = 601489152.

The previous prime is 1916621801. The next prime is 1916621849. The reversal of 1916621808 is 8081266191.

It is a self number, because there is not a number n which added to its sum of digits gives 1916621808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1916621801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 142210 + ... + 155102.

It is an arithmetic number, because the mean of its divisors is an integer number (65553096).

Almost surely, 2^1916621808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1916621808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2622123840).

1916621808 is an abundant number, since it is smaller than the sum of its proper divisors (3327625872).

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

1916621808 is a wasteful number, since it uses less digits than its factorization.

1916621808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13086 (or 13080 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 42.

The square root of 1916621808 is about 43779.2394634717. The cubic root of 1916621808 is about 1242.1636280537.

Adding to 1916621808 its reverse (8081266191), we get a palindrome (9997887999).

The spelling of 1916621808 in words is "one billion, nine hundred sixteen million, six hundred twenty-one thousand, eight hundred eight".