402639321 has 12 divisors (see below), whose sum is σ = 624502032. Its totient is φ = 230079528.

The previous prime is 402639319. The next prime is 402639343. The reversal of 402639321 is 123936204.

It is not a de Polignac number, because 402639321 - 2¹ = 402639319 is a prime.

It is not an unprimeable number, because it can be changed into a prime (402639371) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1369375 + ... + 1369668.

It is an arithmetic number, because the mean of its divisors is an integer number (52041836).

Almost surely, 2^402639321 is an apocalyptic number.

It is an amenable number.

402639321 is a deficient number, since it is larger than the sum of its proper divisors (221862711).

402639321 is a wasteful number, since it uses less digits than its factorization.

402639321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2739060 (or 2739053 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 30.

The square root of 402639321 is about 20065.8745386290. The cubic root of 402639321 is about 738.4233053782.

The spelling of 402639321 in words is "four hundred two million, six hundred thirty-nine thousand, three hundred twenty-one".