321640457 has 8 divisors (see below), whose sum is σ = 326094216. Its totient is φ = 317210112.

The previous prime is 321640399. The next prime is 321640513. The reversal of 321640457 is 754046123.

It can be written as a sum of positive squares in 4 ways, for example, as 213043216 + 108597241 = 14596^2 + 10421^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 321640457 - 2¹⁶ = 321574921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321640157) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 22763 + ... + 34079.

It is an arithmetic number, because the mean of its divisors is an integer number (40761777).

Almost surely, 2^321640457 is an apocalyptic number.

It is an amenable number.

321640457 is a deficient number, since it is larger than the sum of its proper divisors (4453759).

321640457 is a wasteful number, since it uses less digits than its factorization.

321640457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11707.

The product of its (nonzero) digits is 20160, while the sum is 32.

The square root of 321640457 is about 17934.3373727607. The cubic root of 321640457 is about 685.1571962390.

The spelling of 321640457 in words is "three hundred twenty-one million, six hundred forty thousand, four hundred fifty-seven".