998953921 has 4 divisors (see below), whose sum is σ = 1141661632. Its totient is φ = 856246212.

The previous prime is 998953909. The next prime is 998953927. The reversal of 998953921 is 129359899.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 998953921 - 2⁷ = 998953793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (998953927) 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, 71353845 + ... + 71353858.

It is an arithmetic number, because the mean of its divisors is an integer number (285415408).

Almost surely, 2^998953921 is an apocalyptic number.

It is an amenable number.

998953921 is a deficient number, since it is larger than the sum of its proper divisors (142707711).

998953921 is a wasteful number, since it uses less digits than its factorization.

998953921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142707710.

The product of its digits is 1574640, while the sum is 55.

The square root of 998953921 is about 31606.2323126310. The cubic root of 998953921 is about 999.6511853425.

The spelling of 998953921 in words is "nine hundred ninety-eight million, nine hundred fifty-three thousand, nine hundred twenty-one".