398048689921 has 3 divisors (see below), whose sum is σ = 398049320833. Its totient is φ = 398048059010.

The previous prime is 398048689891. The next prime is 398048689933. The reversal of 398048689921 is 129986840893.

The square root of 398048689921 is 630911.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 398048689921 - 2¹⁷ = 398048558849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398048689981) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 315456 + ... + 946366.

Almost surely, 2^398048689921 is an apocalyptic number.

398048689921 is the 630911-st square number.

398048689921 is the 315456-th centered octagonal number.

It is an amenable number.

398048689921 is a deficient number, since it is larger than the sum of its proper divisors (630912).

398048689921 is an frugal number, since it uses more digits than its factorization.

398048689921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1261822 (or 630911 counting only the distinct ones).

The product of its (nonzero) digits is 53747712, while the sum is 67.

The spelling of 398048689921 in words is "three hundred ninety-eight billion, forty-eight million, six hundred eighty-nine thousand, nine hundred twenty-one".