398907807721 has 8 divisors (see below), whose sum is σ = 416451700224. Its totient is φ = 381380588160.

The previous prime is 398907807719. The next prime is 398907807803. The reversal of 398907807721 is 127708709893.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 398907807721 - 2¹ = 398907807719 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 398907807721.

It is not an unprimeable number, because it can be changed into a prime (398907805721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4119321 + ... + 4215046.

It is an arithmetic number, because the mean of its divisors is an integer number (52056462528).

Almost surely, 2^398907807721 is an apocalyptic number.

It is an amenable number.

398907807721 is a deficient number, since it is larger than the sum of its proper divisors (17543892503).

398907807721 is a wasteful number, since it uses less digits than its factorization.

398907807721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8336471.

The product of its (nonzero) digits is 10668672, while the sum is 61.

The spelling of 398907807721 in words is "three hundred ninety-eight billion, nine hundred seven million, eight hundred seven thousand, seven hundred twenty-one".