81746715049321 has 27 divisors (see below), whose sum is σ = 95389336021431. Its totient is φ = 69851022831744.

The previous prime is 81746715049319. The next prime is 81746715049327. The reversal of 81746715049321 is 12394051764718.

The square root of 81746715049321 is 9041389.

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., 33211304555625 + 48535410493696 = 5762925^2 + 6966736^2 .

It is not a de Polignac number, because 81746715049321 - 2¹ = 81746715049319 is a prime.

It is a super-2 number, since 2×81746715049321² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81746715049327) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 22341270390 + ... + 22341274048.

It is a 1-persistent number, because it is pandigital, but 2⋅81746715049321 = 163493430098642 is not.

Almost surely, 2^{81746715049321} is an apocalyptic number.

81746715049321 is the 9041389-th square number.

81746715049321 is the 4520695-th centered octagonal number.

It is an amenable number.

81746715049321 is a deficient number, since it is larger than the sum of its proper divisors (13642620972110).

81746715049321 is an frugal number, since it uses more digits than its factorization.

81746715049321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8038 (or 4019 counting only the distinct ones).

The product of its (nonzero) digits is 10160640, while the sum is 58.

The spelling of 81746715049321 in words is "eighty-one trillion, seven hundred forty-six billion, seven hundred fifteen million, forty-nine thousand, three hundred twenty-one".