321631406 has 8 divisors (see below), whose sum is σ = 490356264. Its totient is φ = 158179320.

The previous prime is 321631399. The next prime is 321631439. The reversal of 321631406 is 604136123.

321631406 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×321631406² = 206893522651073672, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1318040 + ... + 1318283.

It is an arithmetic number, because the mean of its divisors is an integer number (61294533).

Almost surely, 2^321631406 is an apocalyptic number.

321631406 is a deficient number, since it is larger than the sum of its proper divisors (168724858).

321631406 is a wasteful number, since it uses less digits than its factorization.

321631406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2636386.

The product of its (nonzero) digits is 2592, while the sum is 26.

The square root of 321631406 is about 17934.0850338120. The cubic root of 321631406 is about 685.1507693775.

Adding to 321631406 its reverse (604136123), we get a palindrome (925767529).

The spelling of 321631406 in words is "three hundred twenty-one million, six hundred thirty-one thousand, four hundred six".