651182827681 has 9 divisors (see below), whose sum is σ = 652916739699. Its totient is φ = 649453514544.

The previous prime is 651182827679. The next prime is 651182827727. The reversal of 651182827681 is 186728281156.

The square root of 651182827681 is 806959.

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., 207339069025 + 443843758656 = 455345^2 + 666216^2 .

It is not a de Polignac number, because 651182827681 - 2¹ = 651182827679 is a prime.

It is a super-2 number, since 2×651182827681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (651182827601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 392988205 + ... + 392989861.

It is an arithmetic number, because the mean of its divisors is an integer number (72546304411).

Almost surely, 2^651182827681 is an apocalyptic number.

651182827681 is the 806959-th square number.

651182827681 is the 403480-th centered octagonal number.

It is an amenable number.

651182827681 is a deficient number, since it is larger than the sum of its proper divisors (1733912018).

651182827681 is an frugal number, since it uses more digits than its factorization.

651182827681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4288 (or 2144 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 55.

The spelling of 651182827681 in words is "six hundred fifty-one billion, one hundred eighty-two million, eight hundred twenty-seven thousand, six hundred eighty-one".