1223525021 has 4 divisors (see below), whose sum is σ = 1231318332. Its totient is φ = 1215731712.

The previous prime is 1223524987. The next prime is 1223525029. The reversal of 1223525021 is 1205253221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1205253221 = 109 ⋅11057369.

It can be written as a sum of positive squares in 2 ways, for example, as 199204996 + 1024320025 = 14114^2 + 32005^2 .

It is a cyclic number.

It is not a de Polignac number, because 1223525021 - 2¹⁸ = 1223262877 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 (1223525029) 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, 3896420 + ... + 3896733.

It is an arithmetic number, because the mean of its divisors is an integer number (307829583).

Almost surely, 2^1223525021 is an apocalyptic number.

It is an amenable number.

1223525021 is a deficient number, since it is larger than the sum of its proper divisors (7793311).

1223525021 is an equidigital number, since it uses as much as digits as its factorization.

1223525021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7793310.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 1223525021 is about 34978.9225248577. The cubic root of 1223525021 is about 1069.5578634467.

Adding to 1223525021 its reverse (1205253221), we get a palindrome (2428778242).

The spelling of 1223525021 in words is "one billion, two hundred twenty-three million, five hundred twenty-five thousand, twenty-one".