402431993 has 2 divisors, whose sum is σ = 402431994. Its totient is φ = 402431992.

The previous prime is 402431959. The next prime is 402431999. The reversal of 402431993 is 399134204.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 287234704 + 115197289 = 16948^2 + 10733^2 .

It is a cyclic number.

It is not a de Polignac number, because 402431993 - 2¹⁸ = 402169849 is a prime.

It is not a weakly prime, because it can be changed into another prime (402431999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201215996 + 201215997.

It is an arithmetic number, because the mean of its divisors is an integer number (201215997).

Almost surely, 2^402431993 is an apocalyptic number.

It is an amenable number.

402431993 is a deficient number, since it is larger than the sum of its proper divisors (1).

402431993 is an equidigital number, since it uses as much as digits as its factorization.

402431993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 35.

The square root of 402431993 is about 20060.7076894112. The cubic root of 402431993 is about 738.2965400541.

The spelling of 402431993 in words is "four hundred two million, four hundred thirty-one thousand, nine hundred ninety-three".