72181020 has 96 divisors (see below), whose sum is σ = 210825216. Its totient is φ = 18432000.

The previous prime is 72181007. The next prime is 72181037. The reversal of 72181020 is 2018127.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 280732 + ... + 280988.

It is an arithmetic number, because the mean of its divisors is an integer number (2196096).

Almost surely, 2^72181020 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 72181020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105412608).

72181020 is an abundant number, since it is smaller than the sum of its proper divisors (138644196).

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

72181020 is a wasteful number, since it uses less digits than its factorization.

72181020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 451 (or 449 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 21.

The square root of 72181020 is about 8495.9413839786. The cubic root of 72181020 is about 416.3651179946.

Adding to 72181020 its reverse (2018127), we get a palindrome (74199147).

The spelling of 72181020 in words is "seventy-two million, one hundred eighty-one thousand, twenty".