19775808 has 168 divisors, whose sum is σ = 64719200. Its totient is φ = 5723136.

The previous prime is 19775801. The next prime is 19775831. The reversal of 19775808 is 80857791.

It is a Cunningham number, because it is equal to 4447²-1.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19775801) 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, 142203 + ... + 142341.

Almost surely, 2^19775808 is an apocalyptic number.

19775808 is a gapful number since it is divisible by the number (18) 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 19775808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32359600).

19775808 is an abundant number, since it is smaller than the sum of its proper divisors (44943392).

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

19775808 is a wasteful number, since it uses less digits than its factorization.

19775808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 189 (or 176 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The square root of 19775808 is about 4446.9998875646. Note that the first 3 decimals coincide. The cubic root of 19775808 is about 270.4236969067.

The spelling of 19775808 in words is "nineteen million, seven hundred seventy-five thousand, eight hundred eight".