72221020 has 48 divisors (see below), whose sum is σ = 157852800. Its totient is φ = 27722240.

The previous prime is 72220997. The next prime is 72221027. The reversal of 72221020 is 2012227.

It is a junction number, because it is equal to n+sod(n) for n = 72220985 and 72221003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72221027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 138360 + ... + 138880.

It is an arithmetic number, because the mean of its divisors is an integer number (3288600).

Almost surely, 2^72221020 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 72221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78926400).

72221020 is an abundant number, since it is smaller than the sum of its proper divisors (85631780).

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

72221020 is a wasteful number, since it uses less digits than its factorization.

72221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798 (or 796 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 16.

The square root of 72221020 is about 8498.2951231409. The cubic root of 72221020 is about 416.4420150755.

Adding to 72221020 its reverse (2012227), we get a palindrome (74233247).

The spelling of 72221020 in words is "seventy-two million, two hundred twenty-one thousand, twenty".