669109276081 has 27 divisors (see below), whose sum is σ = 698106977857. Its totient is φ = 641304944000.

The previous prime is 669109276037. The next prime is 669109276133. The reversal of 669109276081 is 180672901966.

The square root of 669109276081 is 817991.

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 94120717681 + 574988558400 = 306791^2 + 758280^2 .

It is not a de Polignac number, because 669109276081 - 2³¹ = 666961792433 is a prime.

It is a super-2 number, since 2×669109276081² (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 (669109276181) 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 26 ways as a sum of consecutive naturals, for example, 2381171661 + ... + 2381171941.

Almost surely, 2^669109276081 is an apocalyptic number.

669109276081 is the 817991-st square number.

669109276081 is the 408996-th centered octagonal number.

It is an amenable number.

669109276081 is a deficient number, since it is larger than the sum of its proper divisors (28997701776).

669109276081 is an frugal number, since it uses more digits than its factorization.

669109276081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 786 (or 393 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 55.

The spelling of 669109276081 in words is "six hundred sixty-nine billion, one hundred nine million, two hundred seventy-six thousand, eighty-one".