398878207081 has 4 divisors (see below), whose sum is σ = 398888070100. Its totient is φ = 398868344064.

The previous prime is 398878207019. The next prime is 398878207097. The reversal of 398878207081 is 180702878893.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 267848686681 + 131029520400 = 517541^2 + 361980^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398878207081 is a prime.

It is a super-2 number, since 2×398878207081² (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 (398878277081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4870596 + ... + 4951813.

It is an arithmetic number, because the mean of its divisors is an integer number (99722017525).

Almost surely, 2^398878207081 is an apocalyptic number.

It is an amenable number.

398878207081 is a deficient number, since it is larger than the sum of its proper divisors (9863019).

398878207081 is an equidigital number, since it uses as much as digits as its factorization.

398878207081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9863018.

The product of its (nonzero) digits is 10838016, while the sum is 61.

The spelling of 398878207081 in words is "three hundred ninety-eight billion, eight hundred seventy-eight million, two hundred seven thousand, eighty-one".