321661004 has 12 divisors (see below), whose sum is σ = 643322064. Its totient is φ = 137854704.

The previous prime is 321660973. The next prime is 321661033. The reversal of 321661004 is 400166123.

It is a happy number.

321661004 is an admirable number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5743919 + ... + 5743974.

It is an arithmetic number, because the mean of its divisors is an integer number (53610172).

Almost surely, 2^321661004 is an apocalyptic number.

It is an amenable number.

321661004 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

321661004 is a wasteful number, since it uses less digits than its factorization.

321661004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11487904 (or 11487902 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 321661004 is about 17934.9102032879. The cubic root of 321661004 is about 685.1717856403.

The spelling of 321661004 in words is "three hundred twenty-one million, six hundred sixty-one thousand, four".