820258073761 has 27 divisors (see below), whose sum is σ = 963823977459. Its totient is φ = 696041207568.

The previous prime is 820258073749. The next prime is 820258073779. The reversal of 820258073761 is 167370852028.

The square root of 820258073761 is 905681.

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., 571715942161 + 248542131600 = 756119^2 + 498540^2 .

It is not a de Polignac number, because 820258073761 - 2²⁹ = 819721202849 is a prime.

It is a super-2 number, since 2×820258073761² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is not an unprimeable number, because it can be changed into a prime (820258073711) 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, 691034010 + ... + 691035196.

Almost surely, 2^820258073761 is an apocalyptic number.

820258073761 is the 905681-st square number.

820258073761 is the 452841-st centered octagonal number.

It is an amenable number.

820258073761 is a deficient number, since it is larger than the sum of its proper divisors (143565903698).

820258073761 is an frugal number, since it uses more digits than its factorization.

820258073761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2606 (or 1303 counting only the distinct ones).

The product of its (nonzero) digits is 1128960, while the sum is 49.

Multiplying 820258073761 by its sum of digits (49), we get a square (40192645614289 = 6339767²).

820258073761 divided by its sum of digits (49) gives a square (16739960689 = 129383²).

The spelling of 820258073761 in words is "eight hundred twenty billion, two hundred fifty-eight million, seventy-three thousand, seven hundred sixty-one".