85481971129 has 9 divisors (see below), whose sum is σ = 86924423469. Its totient is φ = 84063084960.

The previous prime is 85481971079. The next prime is 85481971139. The reversal of 85481971129 is 92117918458.

The square root of 85481971129 is 292373.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 3257555625 + 82224415504 = 57075^2 + 286748^2 .

It is not a de Polignac number, because 85481971129 - 2¹¹ = 85481969081 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 85481971129.

It is not an unprimeable number, because it can be changed into a prime (85481971139) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 17832357 + ... + 17837149.

Almost surely, 2^85481971129 is an apocalyptic number.

85481971129 is the 292373-rd square number.

85481971129 is the 146187-th centered octagonal number.

It is an amenable number.

85481971129 is a deficient number, since it is larger than the sum of its proper divisors (1442452340).

85481971129 is an frugal number, since it uses more digits than its factorization.

85481971129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9708 (or 4854 counting only the distinct ones).

The product of its digits is 1451520, while the sum is 55.

The spelling of 85481971129 in words is "eighty-five billion, four hundred eighty-one million, nine hundred seventy-one thousand, one hundred twenty-nine".