19905408936 has 256 divisors, whose sum is σ = 67075776000. Its totient is φ = 5339381760.

The previous prime is 19905408931. The next prime is 19905408989. The reversal of 19905408936 is 63980450991.

19905408936 is a `hidden beast` number, since 1 + 9 + 9 + 0 + 540 + 8 + 93 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (19905408931) 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 63 ways as a sum of consecutive naturals, for example, 14624896 + ... + 14626256.

It is an arithmetic number, because the mean of its divisors is an integer number (262014750).

Almost surely, 2^19905408936 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 19905408936, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33537888000).

19905408936 is an abundant number, since it is smaller than the sum of its proper divisors (47170367064).

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

19905408936 is a wasteful number, since it uses less digits than its factorization.

19905408936 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1969 (or 1959 counting only the distinct ones).

The product of its (nonzero) digits is 2099520, while the sum is 54.

The spelling of 19905408936 in words is "nineteen billion, nine hundred five million, four hundred eight thousand, nine hundred thirty-six".