18961444320 has 384 divisors, whose sum is σ = 74217378816. Its totient is φ = 3962290176.

The previous prime is 18961444261. The next prime is 18961444321. The reversal of 18961444320 is 2344416981.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18961444321) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4671732 + ... + 4675788.

It is an arithmetic number, because the mean of its divisors is an integer number (193274424).

Almost surely, 2^18961444320 is an apocalyptic number.

18961444320 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 18961444320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37108689408).

18961444320 is an abundant number, since it is smaller than the sum of its proper divisors (55255934496).

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

18961444320 is a wasteful number, since it uses less digits than its factorization.

18961444320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4202 (or 4194 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 42.

The spelling of 18961444320 in words is "eighteen billion, nine hundred sixty-one million, four hundred forty-four thousand, three hundred twenty".