666827329 has 45 divisors (see below), whose sum is σ = 853887651. Its totient is φ = 520591680.

The previous prime is 666827327. The next prime is 666827347. The reversal of 666827329 is 923728666.

It is a happy number.

The square root of 666827329 is 25823.

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., 519156225 + 147671104 = 22785^2 + 12152^2 .

It is not a de Polignac number, because 666827329 - 2¹ = 666827327 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (666827327) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 21510544 + ... + 21510574.

Almost surely, 2^666827329 is an apocalyptic number.

666827329 is the 25823-rd square number.

666827329 is the 12912-nd centered octagonal number.

It is an amenable number.

666827329 is a deficient number, since it is larger than the sum of its proper divisors (187060322).

666827329 is an frugal number, since it uses more digits than its factorization.

666827329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124 (or 55 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 49.

The cubic root of 666827329 is about 873.6506348377.

Multiplying 666827329 by its sum of digits (49), we get a square (32674539121 = 180761²).

666827329 divided by its sum of digits (49) gives a square (13608721 = 3689²).

The spelling of 666827329 in words is "six hundred sixty-six million, eight hundred twenty-seven thousand, three hundred twenty-nine".