998691517 has 4 divisors (see below), whose sum is σ = 1009912860. Its totient is φ = 987470176.

The previous prime is 998691497. The next prime is 998691521. The reversal of 998691517 is 715196899.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 715196899 = 1093 ⋅654343.

It can be written as a sum of positive squares in 2 ways, for example, as 342768196 + 655923321 = 18514^2 + 25611^2 .

It is a cyclic number.

It is not a de Polignac number, because 998691517 - 2⁷ = 998691389 is a prime.

It is a super-2 number, since 2×998691517² = 1994769492255522578, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998691527) 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, 5610538 + ... + 5610715.

It is an arithmetic number, because the mean of its divisors is an integer number (252478215).

Almost surely, 2^998691517 is an apocalyptic number.

It is an amenable number.

998691517 is a deficient number, since it is larger than the sum of its proper divisors (11221343).

998691517 is a wasteful number, since it uses less digits than its factorization.

998691517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11221342.

The product of its digits is 1224720, while the sum is 55.

The square root of 998691517 is about 31602.0808966751. The cubic root of 998691517 is about 999.5636486252.

The spelling of 998691517 in words is "nine hundred ninety-eight million, six hundred ninety-one thousand, five hundred seventeen".