661533443 has 2 divisors, whose sum is σ = 661533444. Its totient is φ = 661533442.

The previous prime is 661533421. The next prime is 661533449. The reversal of 661533443 is 344335166.

661533443 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 661533443 - 2¹⁰ = 661532419 is a prime.

It is not a weakly prime, because it can be changed into another prime (661533449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 330766721 + 330766722.

It is an arithmetic number, because the mean of its divisors is an integer number (330766722).

Almost surely, 2^661533443 is an apocalyptic number.

661533443 is a deficient number, since it is larger than the sum of its proper divisors (1).

661533443 is an equidigital number, since it uses as much as digits as its factorization.

661533443 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 77760, while the sum is 35.

The square root of 661533443 is about 25720.2924361291. The cubic root of 661533443 is about 871.3325433261.

It can be divided in two parts, 66153 and 3443, that added together give a palindrome (69596).

The spelling of 661533443 in words is "six hundred sixty-one million, five hundred thirty-three thousand, four hundred forty-three".