19964605440 has 264 divisors, whose sum is σ = 69154341408. Its totient is φ = 4913725440.

The previous prime is 19964605391. The next prime is 19964605483. The reversal of 19964605440 is 4450646991.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 19964605440.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2591995 + ... + 2599685.

Almost surely, 2^19964605440 is an apocalyptic number.

19964605440 is a gapful number since it is divisible by the number (10) 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 19964605440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34577170704).

19964605440 is an abundant number, since it is smaller than the sum of its proper divisors (49189735968).

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

19964605440 is a wasteful number, since it uses less digits than its factorization.

19964605440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7745 (or 7714 counting only the distinct ones).

The product of its (nonzero) digits is 933120, while the sum is 48.

The spelling of 19964605440 in words is "nineteen billion, nine hundred sixty-four million, six hundred five thousand, four hundred forty".