398209932121 has 16 divisors (see below), whose sum is σ = 405923881936. Its totient is φ = 390558744576.

The previous prime is 398209932079. The next prime is 398209932151. The reversal of 398209932121 is 121239902893.

It is the 257621-st star number.

It can be written as a sum of positive squares in 8 ways, for example, as 47436840000 + 350773092121 = 217800^2 + 592261^2 .

It is a 5-Lehmer number, since φ(398209932121) divides (398209932121-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 398209932121 - 2⁷ = 398209931993 is a prime.

It is a super-2 number, since 2×398209932121² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398209932151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48363421 + ... + 48371653.

It is an arithmetic number, because the mean of its divisors is an integer number (25370242621).

Almost surely, 2^398209932121 is an apocalyptic number.

It is an amenable number.

398209932121 is a deficient number, since it is larger than the sum of its proper divisors (7713949815).

398209932121 is a wasteful number, since it uses less digits than its factorization.

398209932121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11932.

The product of its (nonzero) digits is 419904, while the sum is 49.

The spelling of 398209932121 in words is "three hundred ninety-eight billion, two hundred nine million, nine hundred thirty-two thousand, one hundred twenty-one".