661573329 has 8 divisors (see below), whose sum is σ = 892725792. Its totient is φ = 435734880.

The previous prime is 661573327. The next prime is 661573333. The reversal of 661573329 is 923375166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661573329 - 2¹ = 661573327 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (661573327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1328212 + ... + 1328709.

It is an arithmetic number, because the mean of its divisors is an integer number (111590724).

Almost surely, 2^661573329 is an apocalyptic number.

It is an amenable number.

661573329 is a deficient number, since it is larger than the sum of its proper divisors (231152463).

661573329 is a wasteful number, since it uses less digits than its factorization.

661573329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2657007.

The product of its digits is 204120, while the sum is 42.

The square root of 661573329 is about 25721.0678044283. The cubic root of 661573329 is about 871.3500547973.

The spelling of 661573329 in words is "six hundred sixty-one million, five hundred seventy-three thousand, three hundred twenty-nine".