998081139697 has 4 divisors (see below), whose sum is σ = 998083178980. Its totient is φ = 998079100416.

The previous prime is 998081139691. The next prime is 998081139773. The reversal of 998081139697 is 796931180899.

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 379091415616 + 618989724081 = 615704^2 + 786759^2 .

It is a 3-Lehmer number, since φ(998081139697) divides (998081139697-1)³.

It is a cyclic number.

It is not a de Polignac number, because 998081139697 - 2²³ = 998072751089 is a prime.

It is a super-2 number, since 2×998081139697² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (998081139691) 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 3 ways as a sum of consecutive naturals, for example, 203929 + ... + 1427497.

It is an arithmetic number, because the mean of its divisors is an integer number (249520794745).

Almost surely, 2^998081139697 is an apocalyptic number.

998081139697 is the 815713-rd pentagonal number.

It is an amenable number.

998081139697 is a deficient number, since it is larger than the sum of its proper divisors (2039283).

998081139697 is a wasteful number, since it uses less digits than its factorization.

998081139697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2039282.

The product of its (nonzero) digits is 52907904, while the sum is 70.

The spelling of 998081139697 in words is "nine hundred ninety-eight billion, eighty-one million, one hundred thirty-nine thousand, six hundred ninety-seven".