398888416521 has 72 divisors (see below), whose sum is σ = 683834991840. Its totient is φ = 223338560256.

The previous prime is 398888416499. The next prime is 398888416543. The reversal of 398888416521 is 125614888893.

398888416521 is a `hidden beast` number, since 3 + 98 + 8 + 8 + 8 + 4 + 16 + 521 = 666.

It is an interprime number because it is at equal distance from previous prime (398888416499) and next prime (398888416543).

It is not a de Polignac number, because 398888416521 - 2¹⁵ = 398888383753 is a prime.

It is a super-2 number, since 2×398888416521² (a number of 24 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is not an unprimeable number, because it can be changed into a prime (398888416321) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 7962865 + ... + 8012801.

It is an arithmetic number, because the mean of its divisors is an integer number (9497708220).

Almost surely, 2^398888416521 is an apocalyptic number.

It is an amenable number.

398888416521 is a deficient number, since it is larger than the sum of its proper divisors (284946575319).

398888416521 is a wasteful number, since it uses less digits than its factorization.

398888416521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50323 (or 50313 counting only the distinct ones).

The product of its digits is 26542080, while the sum is 63.

It can be divided in two parts, 398888 and 416521, that added together give a square (815409 = 903²).

The spelling of 398888416521 in words is "three hundred ninety-eight billion, eight hundred eighty-eight million, four hundred sixteen thousand, five hundred twenty-one".