398528326681 has 3 divisors (see below), whose sum is σ = 398528957973. Its totient is φ = 398527695390.

The previous prime is 398528326661. The next prime is 398528326687. The reversal of 398528326681 is 186623825893.

It is a happy number.

The square root of 398528326681 is 631291.

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, and also an emirpimes, since its reverse is a distinct semiprime: 186623825893 = 289181 ⋅645353.

It is not a de Polignac number, because 398528326681 - 2¹¹ = 398528324633 is a prime.

It is a super-2 number, since 2×398528326681² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (398528326687) 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, 315646 + ... + 946936.

It is an arithmetic number, because the mean of its divisors is an integer number (132842985991).

Almost surely, 2^398528326681 is an apocalyptic number.

398528326681 is the 631291-st square number.

398528326681 is the 315646-th centered octagonal number.

It is an amenable number.

398528326681 is a deficient number, since it is larger than the sum of its proper divisors (631292).

398528326681 is an frugal number, since it uses more digits than its factorization.

398528326681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1262582 (or 631291 counting only the distinct ones).

The product of its digits is 29859840, while the sum is 61.

The spelling of 398528326681 in words is "three hundred ninety-eight billion, five hundred twenty-eight million, three hundred twenty-six thousand, six hundred eighty-one".