85665679969 has 9 divisors (see below), whose sum is σ = 85985015571. Its totient is φ = 85347529200.

The previous prime is 85665679919. The next prime is 85665680039. The reversal of 85665679969 is 96997656658.

The square root of 85665679969 is 292687.

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., 72004745569 + 13660934400 = 268337^2 + 116880^2 .

It is not a de Polignac number, because 85665679969 - 2¹⁷ = 85665548897 is a prime.

It is a super-2 number, since 2×85665679969² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85665679895 and 85665679904.

It is not an unprimeable number, because it can be changed into a prime (85665679909) 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, 142538269 + ... + 142538869.

It is an arithmetic number, because the mean of its divisors is an integer number (9553890619).

Almost surely, 2^85665679969 is an apocalyptic number.

85665679969 is the 292687-th square number.

85665679969 is the 146344-th centered octagonal number.

It is an amenable number.

85665679969 is a deficient number, since it is larger than the sum of its proper divisors (319335602).

85665679969 is an frugal number, since it uses more digits than its factorization.

85665679969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2176 (or 1088 counting only the distinct ones).

The product of its digits is 1322697600, while the sum is 76.

The spelling of 85665679969 in words is "eighty-five billion, six hundred sixty-five million, six hundred seventy-nine thousand, nine hundred sixty-nine".