19806439464 has 80 divisors (see below), whose sum is σ = 63401580000. Its totient is φ = 5658981408.

The previous prime is 19806439463. The next prime is 19806439561. The reversal of 19806439464 is 46493460891.

It is a happy number.

19806439464 is a `hidden beast` number, since 1 + 98 + 0 + 64 + 39 + 464 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 19806439464.

It is not an unprimeable number, because it can be changed into a prime (19806439463) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2178714 + ... + 2187785.

It is an arithmetic number, because the mean of its divisors is an integer number (792519750).

Almost surely, 2^19806439464 is an apocalyptic number.

19806439464 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

19806439464 is an abundant number, since it is smaller than the sum of its proper divisors (43595140536).

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

19806439464 is a wasteful number, since it uses less digits than its factorization.

19806439464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4366524 (or 4366511 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 54.

It can be divided in two parts, 1980 and 6439464, that added together give a square (6441444 = 2538²).

The spelling of 19806439464 in words is "nineteen billion, eight hundred six million, four hundred thirty-nine thousand, four hundred sixty-four".