661633323 has 16 divisors (see below), whose sum is σ = 958922496. Its totient is φ = 403351200.

The previous prime is 661633283. The next prime is 661633337. The reversal of 661633323 is 323336166.

It is not a de Polignac number, because 661633323 - 2²⁰ = 660584747 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661633363) 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 15 ways as a sum of consecutive naturals, for example, 75103 + ... + 83448.

It is an arithmetic number, because the mean of its divisors is an integer number (59932656).

Almost surely, 2^661633323 is an apocalyptic number.

661633323 is a deficient number, since it is larger than the sum of its proper divisors (297289173).

661633323 is a wasteful number, since it uses less digits than its factorization.

661633323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158674.

The product of its digits is 34992, while the sum is 33.

The square root of 661633323 is about 25722.2340203957. The cubic root of 661633323 is about 871.3763931198.

Adding to 661633323 its reverse (323336166), we get a palindrome (984969489).

The spelling of 661633323 in words is "six hundred sixty-one million, six hundred thirty-three thousand, three hundred twenty-three".