653521 has 8 divisors (see below), whose sum is σ = 720288. Its totient is φ = 592900.

The previous prime is 653519. The next prime is 653537. The reversal of 653521 is 125356.

It is a happy number.

It is not a de Polignac number, because 653521 - 2¹ = 653519 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 653492 and 653501.

It is not an unprimeable number, because it can be changed into a prime (653501) 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, 1086 + ... + 1576.

It is an arithmetic number, because the mean of its divisors is an integer number (90036).

2⁶⁵³⁵²¹ is an apocalyptic number.

It is an amenable number.

653521 is a deficient number, since it is larger than the sum of its proper divisors (66767).

653521 is an equidigital number, since it uses as much as digits as its factorization.

653521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524 (or 502 counting only the distinct ones).

The product of its digits is 900, while the sum is 22.

The square root of 653521 is about 808.4064571736. The cubic root of 653521 is about 86.7800406443.

Adding to 653521 its reverse (125356), we get a palindrome (778877).

It can be divided in two parts, 6535 and 21, that added together give a palindrome (6556).

The spelling of 653521 in words is "six hundred fifty-three thousand, five hundred twenty-one".