2021255720 has 128 divisors (see below), whose sum is σ = 5350665600. Its totient is φ = 679219200.

The previous prime is 2021255693. The next prime is 2021255741. The reversal of 2021255720 is 275521202.

It is a self number, because there is not a number n which added to its sum of digits gives 2021255720.

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, 339812 + ... + 345708.

It is an arithmetic number, because the mean of its divisors is an integer number (41802075).

Almost surely, 2^2021255720 is an apocalyptic number.

2021255720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2021255720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2675332800).

2021255720 is an abundant number, since it is smaller than the sum of its proper divisors (3329409880).

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

2021255720 is a wasteful number, since it uses less digits than its factorization.

2021255720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5979 (or 5975 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 26.

The square root of 2021255720 is about 44958.3776397681. The cubic root of 2021255720 is about 1264.3687519030.

Adding to 2021255720 its reverse (275521202), we get a palindrome (2296776922).

The spelling of 2021255720 in words is "two billion, twenty-one million, two hundred fifty-five thousand, seven hundred twenty".