653891 has 8 divisors (see below), whose sum is σ = 755040. Its totient is φ = 554688.

The previous prime is 653881. The next prime is 653893. The reversal of 653891 is 198356.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-653891 is a prime.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 653891.

It is not an unprimeable number, because it can be changed into a prime (653893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 335 + ... + 1191.

It is an arithmetic number, because the mean of its divisors is an integer number (94380).

2⁶⁵³⁸⁹¹ is an apocalyptic number.

653891 is a deficient number, since it is larger than the sum of its proper divisors (101149).

653891 is a wasteful number, since it uses less digits than its factorization.

653891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973.

The product of its digits is 6480, while the sum is 32.

The square root of 653891 is about 808.6352700693. The cubic root of 653891 is about 86.7964147967.

Subtracting from 653891 its reverse (198356), we obtain a triangular number (455535 = T₉₅₄).

The spelling of 653891 in words is "six hundred fifty-three thousand, eight hundred ninety-one".