321131640 has 64 divisors (see below), whose sum is σ = 966972960. Its totient is φ = 85317120.

The previous prime is 321131623. The next prime is 321131641. The reversal of 321131640 is 46131123.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (321131641) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 28410 + ... + 38070.

Almost surely, 2^321131640 is an apocalyptic number.

321131640 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 321131640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (483486480).

321131640 is an abundant number, since it is smaller than the sum of its proper divisors (645841320).

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

321131640 is a wasteful number, since it uses less digits than its factorization.

321131640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9952 (or 9948 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 321131640 is about 17920.1462047607. The cubic root of 321131640 is about 684.7957122533.

Adding to 321131640 its reverse (46131123), we get a palindrome (367262763).

The spelling of 321131640 in words is "three hundred twenty-one million, one hundred thirty-one thousand, six hundred forty".