402043431221 has 2 divisors, whose sum is σ = 402043431222. Its totient is φ = 402043431220.

The previous prime is 402043431211. The next prime is 402043431247. The reversal of 402043431221 is 122134340204.

It is an a-pointer prime, because the next prime (402043431247) can be obtained adding 402043431221 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 392829351121 + 9214080100 = 626761^2 + 95990^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402043431221 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402043431211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201021715610 + 201021715611.

It is an arithmetic number, because the mean of its divisors is an integer number (201021715611).

Almost surely, 2^402043431221 is an apocalyptic number.

It is an amenable number.

402043431221 is a deficient number, since it is larger than the sum of its proper divisors (1).

402043431221 is an equidigital number, since it uses as much as digits as its factorization.

402043431221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 402043431221 its reverse (122134340204), we get a palindrome (524177771425).

The spelling of 402043431221 in words is "four hundred two billion, forty-three million, four hundred thirty-one thousand, two hundred twenty-one".