321620666 has 8 divisors (see below), whose sum is σ = 483246324. Its totient is φ = 160538560.

The previous prime is 321620659. The next prime is 321620681. The reversal of 321620666 is 666026123.

It can be written as a sum of positive squares in 2 ways, for example, as 303770041 + 17850625 = 17429^2 + 4225^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 134405 + ... + 136776.

Almost surely, 2^321620666 is an apocalyptic number.

321620666 is a deficient number, since it is larger than the sum of its proper divisors (161625658).

321620666 is a wasteful number, since it uses less digits than its factorization.

321620666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271776.

The product of its (nonzero) digits is 15552, while the sum is 32.

The square root of 321620666 is about 17933.7856014841. The cubic root of 321620666 is about 685.1431430481.

Adding to 321620666 its reverse (666026123), we get a palindrome (987646789).

The spelling of 321620666 in words is "three hundred twenty-one million, six hundred twenty thousand, six hundred sixty-six".