623521 has 2 divisors, whose sum is σ = 623522. Its totient is φ = 623520.

The previous prime is 623477. The next prime is 623531. The reversal of 623521 is 125326.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 384400 + 239121 = 620^2 + 489^2 .

It is a cyclic number.

It is not a de Polignac number, because 623521 - 2⁷ = 623393 is a prime.

It is a d-powerful number, because it can be written as 6⁴ + 2⁷ + 5⁷ + 3⁹ + 2¹⁹ + 1 .

It is a plaindrome in base 14.

It is not a weakly prime, because it can be changed into another prime (623531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311760 + 311761.

It is an arithmetic number, because the mean of its divisors is an integer number (311761).

2⁶²³⁵²¹ is an apocalyptic number.

It is an amenable number.

623521 is a deficient number, since it is larger than the sum of its proper divisors (1).

623521 is an equidigital number, since it uses as much as digits as its factorization.

623521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 360, while the sum is 19.

The square root of 623521 is about 789.6334592708. The cubic root of 623521 is about 85.4313026146.

Adding to 623521 its reverse (125326), we get a palindrome (748847).

The spelling of 623521 in words is "six hundred twenty-three thousand, five hundred twenty-one".