2021705256 has 16 divisors (see below), whose sum is σ = 5054263200. Its totient is φ = 673901744.

The previous prime is 2021705251. The next prime is 2021705281. The reversal of 2021705256 is 6525071202.

It is not an unprimeable number, because it can be changed into a prime (2021705251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42118836 + ... + 42118883.

It is an arithmetic number, because the mean of its divisors is an integer number (315891450).

Almost surely, 2^2021705256 is an apocalyptic number.

It is an amenable number.

2021705256 is an abundant number, since it is smaller than the sum of its proper divisors (3032557944).

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

2021705256 is a wasteful number, since it uses less digits than its factorization.

2021705256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84237728 (or 84237724 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 2021705256 is about 44963.3768304828. The cubic root of 2021705256 is about 1264.4624786450.

Adding to 2021705256 its reverse (6525071202), we get a palindrome (8546776458).

The spelling of 2021705256 in words is "two billion, twenty-one million, seven hundred five thousand, two hundred fifty-six".