72221443644 has 96 divisors (see below), whose sum is σ = 196537259520. Its totient is φ = 20213077248.

The previous prime is 72221443639. The next prime is 72221443649. The reversal of 72221443644 is 44634412227.

It is an interprime number because it is at equal distance from previous prime (72221443639) and next prime (72221443649).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72221443649) 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, 2850022 + ... + 2875250.

It is an arithmetic number, because the mean of its divisors is an integer number (2047263120).

Almost surely, 2^72221443644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 72221443644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (98268629760).

72221443644 is an abundant number, since it is smaller than the sum of its proper divisors (124315815876).

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

72221443644 is a wasteful number, since it uses less digits than its factorization.

72221443644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25939 (or 25937 counting only the distinct ones).

The product of its digits is 258048, while the sum is 39.

The spelling of 72221443644 in words is "seventy-two billion, two hundred twenty-one million, four hundred forty-three thousand, six hundred forty-four".