720020021800 has 48 divisors (see below), whose sum is σ = 1688861174940. Its totient is φ = 285459256320.

The previous prime is 720020021779. The next prime is 720020021803. The reversal of 720020021800 is 8120020027.

It can be written as a sum of positive squares in 6 ways, for example, as 203958817924 + 516061203876 = 451618^2 + 718374^2 .

It is not an unprimeable number, because it can be changed into a prime (720020021803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15907047 + ... + 15952246.

Almost surely, 2^720020021800 is an apocalyptic number.

It is an amenable number.

720020021800 is an abundant number, since it is smaller than the sum of its proper divisors (968841153140).

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

720020021800 is a wasteful number, since it uses less digits than its factorization.

720020021800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31859422 (or 31859413 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 22.

Adding to 720020021800 its reverse (8120020027), we get a palindrome (728140041827).

The spelling of 720020021800 in words is "seven hundred twenty billion, twenty million, twenty-one thousand, eight hundred".