998405287 has 4 divisors (see below), whose sum is σ = 1089169416. Its totient is φ = 907641160.

The previous prime is 998405281. The next prime is 998405311. The reversal of 998405287 is 782504899.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 782504899 = 11 ⋅71136809.

It is a cyclic number.

It is not a de Polignac number, because 998405287 - 2¹⁵ = 998372519 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998405281) 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, 45382048 + ... + 45382069.

It is an arithmetic number, because the mean of its divisors is an integer number (272292354).

Almost surely, 2^998405287 is an apocalyptic number.

998405287 is a deficient number, since it is larger than the sum of its proper divisors (90764129).

998405287 is a wasteful number, since it uses less digits than its factorization.

998405287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90764128.

The product of its (nonzero) digits is 1451520, while the sum is 52.

The square root of 998405287 is about 31597.5519146658. The cubic root of 998405287 is about 999.4681461817.

The spelling of 998405287 in words is "nine hundred ninety-eight million, four hundred five thousand, two hundred eighty-seven".