321138664 has 32 divisors (see below), whose sum is σ = 750715200. Its totient is φ = 125118720.

The previous prime is 321138661. The next prime is 321138731. The reversal of 321138664 is 466831123.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (321138661) 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, 260049 + ... + 261280.

It is an arithmetic number, because the mean of its divisors is an integer number (23459850).

Almost surely, 2^321138664 is an apocalyptic number.

It is an amenable number.

321138664 is an abundant number, since it is smaller than the sum of its proper divisors (429576536).

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

321138664 is a wasteful number, since it uses less digits than its factorization.

321138664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 521353 (or 521349 counting only the distinct ones).

The product of its digits is 20736, while the sum is 34.

The square root of 321138664 is about 17920.3421842330. The cubic root of 321138664 is about 684.8007049826.

Adding to 321138664 its reverse (466831123), we get a palindrome (787969787).

The spelling of 321138664 in words is "three hundred twenty-one million, one hundred thirty-eight thousand, six hundred sixty-four".