398831923421 has 2 divisors, whose sum is σ = 398831923422. Its totient is φ = 398831923420.

The previous prime is 398831923351. The next prime is 398831923423. The reversal of 398831923421 is 124329138893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 315838380025 + 82993543396 = 561995^2 + 288086^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398831923421 is a prime.

Together with 398831923423, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398831923423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199415961710 + 199415961711.

It is an arithmetic number, because the mean of its divisors is an integer number (199415961711).

Almost surely, 2^398831923421 is an apocalyptic number.

It is an amenable number.

398831923421 is a deficient number, since it is larger than the sum of its proper divisors (1).

398831923421 is an equidigital number, since it uses as much as digits as its factorization.

398831923421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2239488, while the sum is 53.

The spelling of 398831923421 in words is "three hundred ninety-eight billion, eight hundred thirty-one million, nine hundred twenty-three thousand, four hundred twenty-one".