661533433 has 4 divisors (see below), whose sum is σ = 721672848. Its totient is φ = 601394020.

The previous prime is 661533421. The next prime is 661533443. The reversal of 661533433 is 334335166.

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 not a de Polignac number, because 661533433 - 2¹⁷ = 661402361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661533443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30069691 + ... + 30069712.

It is an arithmetic number, because the mean of its divisors is an integer number (180418212).

Almost surely, 2^661533433 is an apocalyptic number.

It is an amenable number.

661533433 is a deficient number, since it is larger than the sum of its proper divisors (60139415).

661533433 is a wasteful number, since it uses less digits than its factorization.

661533433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60139414.

The product of its digits is 58320, while the sum is 34.

The square root of 661533433 is about 25720.2922417301. The cubic root of 661533433 is about 871.3325389357.

Adding to 661533433 its reverse (334335166), we get a palindrome (995868599).

The spelling of 661533433 in words is "six hundred sixty-one million, five hundred thirty-three thousand, four hundred thirty-three".