321690 has 16 divisors (see below), whose sum is σ = 772128. Its totient is φ = 85776.

The previous prime is 321679. The next prime is 321707. The reversal of 321690 is 96123.

It is a super-2 number, since 2×321690² = 206968912200, which contains 22 as substring.

It is an Ulam number.

It is an alternating number because its digits alternate between odd and even.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 321690.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5332 + ... + 5391.

It is an arithmetic number, because the mean of its divisors is an integer number (48258).

2³²¹⁶⁹⁰ is an apocalyptic number.

321690 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

321690 is an abundant number, since it is smaller than the sum of its proper divisors (450438).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

321690 is a wasteful number, since it uses less digits than its factorization.

321690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10733.

The product of its (nonzero) digits is 324, while the sum is 21.

The square root of 321690 is about 567.1772209812. The cubic root of 321690 is about 68.5192373199.

The spelling of 321690 in words is "three hundred twenty-one thousand, six hundred ninety".