998388136261 has 4 divisors (see below), whose sum is σ = 999187487500. Its totient is φ = 997588785024.

The previous prime is 998388136223. The next prime is 998388136267. The reversal of 998388136261 is 162631883899.

998388136261 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 162631883899 = 419 ⋅388142921.

It can be written as a sum of positive squares in 2 ways, for example, as 744563620161 + 253824516100 = 862881^2 + 503810^2 .

It is a cyclic number.

It is not a de Polignac number, because 998388136261 - 2¹¹ = 998388134213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 998388136193 and 998388136202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998388136267) 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, 399673746 + ... + 399676243.

It is an arithmetic number, because the mean of its divisors is an integer number (249796871875).

Almost surely, 2^998388136261 is an apocalyptic number.

It is an amenable number.

998388136261 is a deficient number, since it is larger than the sum of its proper divisors (799351239).

998388136261 is a wasteful number, since it uses less digits than its factorization.

998388136261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799351238.

The product of its digits is 26873856, while the sum is 64.

The spelling of 998388136261 in words is "nine hundred ninety-eight billion, three hundred eighty-eight million, one hundred thirty-six thousand, two hundred sixty-one".