123521221 has 4 divisors (see below), whose sum is σ = 123875500. Its totient is φ = 123166944.

The previous prime is 123521197. The next prime is 123521227. The reversal of 123521221 is 122125321.

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

It can be written as a sum of positive squares in 2 ways, for example, as 90516196 + 33005025 = 9514^2 + 5745^2 .

It is a cyclic number.

It is not a de Polignac number, because 123521221 - 2⁷ = 123521093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123521227) 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, 176616 + ... + 177313.

It is an arithmetic number, because the mean of its divisors is an integer number (30968875).

Almost surely, 2^123521221 is an apocalyptic number.

It is an amenable number.

123521221 is a deficient number, since it is larger than the sum of its proper divisors (354279).

123521221 is an equidigital number, since it uses as much as digits as its factorization.

123521221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 354278.

The product of its digits is 240, while the sum is 19.

The square root of 123521221 is about 11114.0101223636. The cubic root of 123521221 is about 498.0204679146.

Adding to 123521221 its reverse (122125321), we get a palindrome (245646542).

The spelling of 123521221 in words is "one hundred twenty-three million, five hundred twenty-one thousand, two hundred twenty-one".