653998 has 4 divisors (see below), whose sum is σ = 981000. Its totient is φ = 326998.

The previous prime is 653993. The next prime is 654001. The reversal of 653998 is 899356.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 653998.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (653993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 163498 + ... + 163501.

It is an arithmetic number, because the mean of its divisors is an integer number (245250).

2⁶⁵³⁹⁹⁸ is an apocalyptic number.

653998 is a deficient number, since it is larger than the sum of its proper divisors (327002).

653998 is a wasteful number, since it uses less digits than its factorization.

653998 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327001.

The product of its digits is 58320, while the sum is 40.

The square root of 653998 is about 808.7014282169. The cubic root of 653998 is about 86.8011488731.

The spelling of 653998 in words is "six hundred fifty-three thousand, nine hundred ninety-eight".