72020211221 has 12 divisors (see below), whose sum is σ = 88706767788. Its totient is φ = 58100337792.

The previous prime is 72020211217. The next prime is 72020211223. The reversal of 72020211221 is 12211202027.

It can be written as a sum of positive squares in 2 ways, for example, as 27546040900 + 44474170321 = 165970^2 + 210889^2 .

It is not a de Polignac number, because 72020211221 - 2² = 72020211217 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 72020211193 and 72020211202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (72020211223) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 43228586 + ... + 43230251.

It is an arithmetic number, because the mean of its divisors is an integer number (7392230649).

Almost surely, 2^72020211221 is an apocalyptic number.

It is an amenable number.

72020211221 is a deficient number, since it is larger than the sum of its proper divisors (16686556567).

72020211221 is a wasteful number, since it uses less digits than its factorization.

72020211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86458868 (or 86458861 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 72020211221 its reverse (12211202027), we get a palindrome (84231413248).

The spelling of 72020211221 in words is "seventy-two billion, twenty million, two hundred eleven thousand, two hundred twenty-one".