402131321 has 8 divisors (see below), whose sum is σ = 412203624. Its totient is φ = 392071680.

The previous prime is 402131297. The next prime is 402131339. The reversal of 402131321 is 123131204.

It can be written as a sum of positive squares in 4 ways, for example, as 5125696 + 397005625 = 2264^2 + 19925^2 .

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 402131321 - 2¹⁸ = 401869177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 402131321.

It is not an unprimeable number, because it can be changed into a prime (402131341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 115421 + ... + 118853.

It is an arithmetic number, because the mean of its divisors is an integer number (51525453).

Almost surely, 2^402131321 is an apocalyptic number.

402131321 is a gapful number since it is divisible by the number (41) formed by its first and last digit.

It is an amenable number.

402131321 is a deficient number, since it is larger than the sum of its proper divisors (10072303).

402131321 is a wasteful number, since it uses less digits than its factorization.

402131321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6331.

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 402131321 is about 20053.2122364473. The cubic root of 402131321 is about 738.1126245863.

Adding to 402131321 its reverse (123131204), we get a palindrome (525262525).

The spelling of 402131321 in words is "four hundred two million, one hundred thirty-one thousand, three hundred twenty-one".