19809659604 has 96 divisors (see below), whose sum is σ = 55222142976. Its totient is φ = 5404037760.

The previous prime is 19809659599. The next prime is 19809659609. The reversal of 19809659604 is 40695690891.

It is an interprime number because it is at equal distance from previous prime (19809659599) and next prime (19809659609).

It is a super-2 number, since 2×19809659604² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19809659609) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1094194 + ... + 1112150.

It is an arithmetic number, because the mean of its divisors is an integer number (575230656).

Almost surely, 2^19809659604 is an apocalyptic number.

19809659604 is a gapful number since it is divisible by the number (14) 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 19809659604, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27611071488).

19809659604 is an abundant number, since it is smaller than the sum of its proper divisors (35412483372).

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

19809659604 is a wasteful number, since it uses less digits than its factorization.

19809659604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18565 (or 18563 counting only the distinct ones).

The product of its (nonzero) digits is 4199040, while the sum is 57.

The spelling of 19809659604 in words is "nineteen billion, eight hundred nine million, six hundred fifty-nine thousand, six hundred four".