2021185395856 has 135 divisors (see below), whose sum is σ = 4370276145753. Its totient is φ = 904873432320.

The previous prime is 2021185395787. The next prime is 2021185395913. The reversal of 2021185395856 is 6585935811202.

The square root of 2021185395856 is 1421684.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 1847196301456 + 173989094400 = 1359116^2 + 417120^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021185395797 and 2021185395806.

It is an unprimeable number.

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 26 ways as a sum of consecutive naturals, for example, 4941773380 + ... + 4941773788.

Almost surely, 2^{2021185395856} is an apocalyptic number.

2021185395856 is the 1421684-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2021185395856

2021185395856 is an abundant number, since it is smaller than the sum of its proper divisors (2349090749897).

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

2021185395856 is an frugal number, since it uses more digits than its factorization.

2021185395856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1006 (or 501 counting only the distinct ones).

The product of its (nonzero) digits is 5184000, while the sum is 55.

The spelling of 2021185395856 in words is "two trillion, twenty-one billion, one hundred eighty-five million, three hundred ninety-five thousand, eight hundred fifty-six".