402431641 has 2 divisors, whose sum is σ = 402431642. Its totient is φ = 402431640.

The previous prime is 402431639. The next prime is 402431651. The reversal of 402431641 is 146134204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211411600 + 191020041 = 14540^2 + 13821^2 .

It is a cyclic number.

It is not a de Polignac number, because 402431641 - 2¹ = 402431639 is a prime.

Together with 402431639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (402431651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201215820 + 201215821.

It is an arithmetic number, because the mean of its divisors is an integer number (201215821).

Almost surely, 2^402431641 is an apocalyptic number.

402431641 is the 12688-th centered pentagonal number.

It is an amenable number.

402431641 is a deficient number, since it is larger than the sum of its proper divisors (1).

402431641 is an equidigital number, since it uses as much as digits as its factorization.

402431641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 402431641 is about 20060.6989160398. The cubic root of 402431641 is about 738.2963247958.

Adding to 402431641 its reverse (146134204), we get a palindrome (548565845).

The spelling of 402431641 in words is "four hundred two million, four hundred thirty-one thousand, six hundred forty-one".