1222271521 has 3 divisors (see below), whose sum is σ = 1222306483. Its totient is φ = 1222236560.

The previous prime is 1222271513. The next prime is 1222271537. The reversal of 1222271521 is 1251722221.

It is a happy number.

The square root of 1222271521 is 34961.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1251722221 = 157 ⋅7972753.

It can be written as a sum of positive squares in only one way, i.e., 491109921 + 731161600 = 22161^2 + 27040^2 .

It is not a de Polignac number, because 1222271521 - 2³ = 1222271513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1222271591) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 17481 + ... + 52441.

Almost surely, 2^1222271521 is an apocalyptic number.

1222271521 is the 34961-st square number.

1222271521 is the 17481-st centered octagonal number.

It is an amenable number.

1222271521 is a deficient number, since it is larger than the sum of its proper divisors (34962).

1222271521 is an frugal number, since it uses more digits than its factorization.

1222271521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69922 (or 34961 counting only the distinct ones).

The product of its digits is 1120, while the sum is 25.

The cubic root of 1222271521 is about 1069.1924850346.

Multiplying 1222271521 by its sum of digits (25), we get a square (30556788025 = 174805²).

Adding to 1222271521 its reverse (1251722221), we get a palindrome (2473993742).

The spelling of 1222271521 in words is "one billion, two hundred twenty-two million, two hundred seventy-one thousand, five hundred twenty-one".