661544233 has 4 divisors (see below), whose sum is σ = 756050560. Its totient is φ = 567037908.

The previous prime is 661544227. The next prime is 661544237. The reversal of 661544233 is 332445166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-661544233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661544237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47253153 + ... + 47253166.

It is an arithmetic number, because the mean of its divisors is an integer number (189012640).

Almost surely, 2^661544233 is an apocalyptic number.

It is an amenable number.

661544233 is a deficient number, since it is larger than the sum of its proper divisors (94506327).

661544233 is an equidigital number, since it uses as much as digits as its factorization.

661544233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94506326.

The product of its digits is 51840, while the sum is 34.

The square root of 661544233 is about 25720.5021918313. The cubic root of 661544233 is about 871.3372806160.

Adding to 661544233 its reverse (332445166), we get a palindrome (993989399).

The spelling of 661544233 in words is "six hundred sixty-one million, five hundred forty-four thousand, two hundred thirty-three".