661203321 has 8 divisors (see below), whose sum is σ = 933463584. Its totient is φ = 414872640.

The previous prime is 661203311. The next prime is 661203349. The reversal of 661203321 is 123302166.

It is a happy number.

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

It is not a de Polignac number, because 661203321 - 2⁵ = 661203289 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 661203291 and 661203300.

It is not an unprimeable number, because it can be changed into a prime (661203311) 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, 6482335 + ... + 6482436.

It is an arithmetic number, because the mean of its divisors is an integer number (116682948).

Almost surely, 2^661203321 is an apocalyptic number.

It is an amenable number.

661203321 is a deficient number, since it is larger than the sum of its proper divisors (272260263).

661203321 is a wasteful number, since it uses less digits than its factorization.

661203321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12964791.

The product of its (nonzero) digits is 1296, while the sum is 24.

The square root of 661203321 is about 25713.8740955151. The cubic root of 661203321 is about 871.1875801824.

Adding to 661203321 its reverse (123302166), we get a palindrome (784505487).

The spelling of 661203321 in words is "six hundred sixty-one million, two hundred three thousand, three hundred twenty-one".