321798640 has 20 divisors (see below), whose sum is σ = 748182024. Its totient is φ = 128719424.

The previous prime is 321798637. The next prime is 321798689. The reversal of 321798640 is 46897123.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 321798593 and 321798602.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2011162 + ... + 2011321.

Almost surely, 2^321798640 is an apocalyptic number.

It is an amenable number.

321798640 is an abundant number, since it is smaller than the sum of its proper divisors (426383384).

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

321798640 is a wasteful number, since it uses less digits than its factorization.

321798640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4022496 (or 4022490 counting only the distinct ones).

The product of its (nonzero) digits is 72576, while the sum is 40.

The square root of 321798640 is about 17938.7468904603. The cubic root of 321798640 is about 685.2694980925.

The spelling of 321798640 in words is "three hundred twenty-one million, seven hundred ninety-eight thousand, six hundred forty".