402132221 has 4 divisors (see below), whose sum is σ = 406278012. Its totient is φ = 397986432.

The previous prime is 402132197. The next prime is 402132281. The reversal of 402132221 is 122231204.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 236083225 + 166048996 = 15365^2 + 12886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402132221 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 402132221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402132281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2072750 + ... + 2072943.

It is an arithmetic number, because the mean of its divisors is an integer number (101569503).

Almost surely, 2^402132221 is an apocalyptic number.

It is an amenable number.

402132221 is a deficient number, since it is larger than the sum of its proper divisors (4145791).

402132221 is an equidigital number, since it uses as much as digits as its factorization.

402132221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4145790.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 402132221 is about 20053.2346767298. The cubic root of 402132221 is about 738.1131752363.

Adding to 402132221 its reverse (122231204), we get a palindrome (524363425).

The spelling of 402132221 in words is "four hundred two million, one hundred thirty-two thousand, two hundred twenty-one".