1213261563 has 4 divisors (see below), whose sum is σ = 1617682088. Its totient is φ = 808841040.

The previous prime is 1213261541. The next prime is 1213261571. The reversal of 1213261563 is 3651623121.

1213261563 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3651623121 = 3 ⋅1217207707.

It is not a de Polignac number, because 1213261563 - 2⁶ = 1213261499 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1213261563.

It is not an unprimeable number, because it can be changed into a prime (1213261583) 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, 202210258 + ... + 202210263.

It is an arithmetic number, because the mean of its divisors is an integer number (404420522).

Almost surely, 2^1213261563 is an apocalyptic number.

1213261563 is a deficient number, since it is larger than the sum of its proper divisors (404420525).

1213261563 is an equidigital number, since it uses as much as digits as its factorization.

1213261563 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404420524.

The product of its digits is 6480, while the sum is 30.

The square root of 1213261563 is about 34831.9043837686. The cubic root of 1213261563 is about 1066.5588237434.

Adding to 1213261563 its reverse (3651623121), we get a palindrome (4864884684).

The spelling of 1213261563 in words is "one billion, two hundred thirteen million, two hundred sixty-one thousand, five hundred sixty-three".