398037221 has 2 divisors, whose sum is σ = 398037222. Its totient is φ = 398037220.

The previous prime is 398037191. The next prime is 398037229. The reversal of 398037221 is 122730893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 395572321 + 2464900 = 19889^2 + 1570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398037221 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398037229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199018610 + 199018611.

It is an arithmetic number, because the mean of its divisors is an integer number (199018611).

Almost surely, 2^398037221 is an apocalyptic number.

It is an amenable number.

398037221 is a deficient number, since it is larger than the sum of its proper divisors (1).

398037221 is an equidigital number, since it uses as much as digits as its factorization.

398037221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 398037221 is about 19950.8701815234. The cubic root of 398037221 is about 735.5991665132.

The spelling of 398037221 in words is "three hundred ninety-eight million, thirty-seven thousand, two hundred twenty-one".