1223500021 has 2 divisors, whose sum is σ = 1223500022. Its totient is φ = 1223500020.

The previous prime is 1223500007. The next prime is 1223500067. The reversal of 1223500021 is 1200053221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 971007921 + 252492100 = 31161^2 + 15890^2 .

It is a cyclic number.

It is not a de Polignac number, because 1223500021 - 2²⁹ = 686629109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1223499968 and 1223500004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1223500121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 611750010 + 611750011.

It is an arithmetic number, because the mean of its divisors is an integer number (611750011).

Almost surely, 2^1223500021 is an apocalyptic number.

It is an amenable number.

1223500021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1223500021 is an equidigital number, since it uses as much as digits as its factorization.

1223500021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 1223500021 is about 34978.5651649692. The cubic root of 1223500021 is about 1069.5505787221.

Adding to 1223500021 its reverse (1200053221), we get a palindrome (2423553242).

The spelling of 1223500021 in words is "one billion, two hundred twenty-three million, five hundred thousand, twenty-one".