19408664805 has 128 divisors (see below), whose sum is σ = 34488115200. Its totient is φ = 9281654784.

The previous prime is 19408664801. The next prime is 19408664809. The reversal of 19408664805 is 50846680491.

It is an interprime number because it is at equal distance from previous prime (19408664801) and next prime (19408664809).

It is not a de Polignac number, because 19408664805 - 2² = 19408664801 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19408664801) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 108428206 + ... + 108428384.

It is an arithmetic number, because the mean of its divisors is an integer number (269438400).

Almost surely, 2^19408664805 is an apocalyptic number.

19408664805 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

19408664805 is a deficient number, since it is larger than the sum of its proper divisors (15079450395).

19408664805 is a wasteful number, since it uses less digits than its factorization.

19408664805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 443.

The product of its (nonzero) digits is 1658880, while the sum is 51.

The spelling of 19408664805 in words is "nineteen billion, four hundred eight million, six hundred sixty-four thousand, eight hundred five".