221423523 has 4 divisors (see below), whose sum is σ = 295231368. Its totient is φ = 147615680.

The previous prime is 221423479. The next prime is 221423539. The reversal of 221423523 is 325324122.

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

It is a cyclic number.

It is not a de Polignac number, because 221423523 - 2⁶ = 221423459 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221423493 and 221423502.

It is not an unprimeable number, because it can be changed into a prime (221423563) 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, 36903918 + ... + 36903923.

It is an arithmetic number, because the mean of its divisors is an integer number (73807842).

Almost surely, 2^221423523 is an apocalyptic number.

221423523 is a deficient number, since it is larger than the sum of its proper divisors (73807845).

221423523 is an equidigital number, since it uses as much as digits as its factorization.

221423523 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73807844.

The product of its digits is 2880, while the sum is 24.

The square root of 221423523 is about 14880.3065492617. The cubic root of 221423523 is about 604.9803267514.

Adding to 221423523 its reverse (325324122), we get a palindrome (546747645).

The spelling of 221423523 in words is "two hundred twenty-one million, four hundred twenty-three thousand, five hundred twenty-three".