998653221 has 6 divisors (see below), whose sum is σ = 1442499110. Its totient is φ = 665768808.

The previous prime is 998653211. The next prime is 998653223. The reversal of 998653221 is 122356899.

998653221 is a `hidden beast` number, since 9 + 98 + 6 + 532 + 21 = 666.

It can be written as a sum of positive squares in only one way, i.e., 871076196 + 127577025 = 29514^2 + 11295^2 .

It is not a de Polignac number, because 998653221 - 2⁷ = 998653093 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (998653223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55480726 + ... + 55480743.

Almost surely, 2^998653221 is an apocalyptic number.

It is an amenable number.

998653221 is a deficient number, since it is larger than the sum of its proper divisors (443845889).

998653221 is a wasteful number, since it uses less digits than its factorization.

998653221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110961475 (or 110961472 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 998653221 is about 31601.4749813992. The cubic root of 998653221 is about 999.5508719809.

The spelling of 998653221 in words is "nine hundred ninety-eight million, six hundred fifty-three thousand, two hundred twenty-one".