2820857970681 has 27 divisors (see below), whose sum is σ = 4187949301263. Its totient is φ = 1829624783760.

The previous prime is 2820857970659. The next prime is 2820857970691. The reversal of 2820857970681 is 1860797580282.

The square root of 2820857970681 is 1679541.

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., 2524142450025 + 296715520656 = 1588755^2 + 544716^2 .

It is not a de Polignac number, because 2820857970681 - 2¹⁷ = 2820857839609 is a prime.

It is a super-2 number, since 2×2820857970681² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (2820857970611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 186421486 + ... + 186436616.

Almost surely, 2^{2820857970681} is an apocalyptic number.

2820857970681 is the 1679541-st square number.

2820857970681 is the 839771-st centered octagonal number.

It is an amenable number.

2820857970681 is a deficient number, since it is larger than the sum of its proper divisors (1367091330582).

2820857970681 is an frugal number, since it uses more digits than its factorization.

2820857970681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30342 (or 15171 counting only the distinct ones).

The product of its (nonzero) digits is 27095040, while the sum is 63.

The spelling of 2820857970681 in words is "two trillion, eight hundred twenty billion, eight hundred fifty-seven million, nine hundred seventy thousand, six hundred eighty-one".