398209931993 has 2 divisors, whose sum is σ = 398209931994. Its totient is φ = 398209931992.

The previous prime is 398209931957. The next prime is 398209932017. The reversal of 398209931993 is 399139902893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 331370619904 + 66839312089 = 575648^2 + 258533^2 .

It is a cyclic number.

It is not a de Polignac number, because 398209931993 - 2¹⁰ = 398209930969 is a prime.

It is a super-2 number, since 2×398209931993² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (398209931593) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199104965996 + 199104965997.

It is an arithmetic number, because the mean of its divisors is an integer number (199104965997).

Almost surely, 2^398209931993 is an apocalyptic number.

It is an amenable number.

398209931993 is a deficient number, since it is larger than the sum of its proper divisors (1).

398209931993 is an equidigital number, since it uses as much as digits as its factorization.

398209931993 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25509168, while the sum is 65.

The spelling of 398209931993 in words is "three hundred ninety-eight billion, two hundred nine million, nine hundred thirty-one thousand, nine hundred ninety-three".