1221513235 has 16 divisors (see below), whose sum is σ = 1487253600. Its totient is φ = 963023616.

The previous prime is 1221513197. The next prime is 1221513239. The reversal of 1221513235 is 5323151221.

It is a cyclic number.

It is not a de Polignac number, because 1221513235 - 2⁷ = 1221513107 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1221513239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88801 + ... + 101629.

It is an arithmetic number, because the mean of its divisors is an integer number (92953350).

Almost surely, 2^1221513235 is an apocalyptic number.

1221513235 is a deficient number, since it is larger than the sum of its proper divisors (265740365).

1221513235 is a wasteful number, since it uses less digits than its factorization.

1221513235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13110.

The product of its digits is 1800, while the sum is 25.

The square root of 1221513235 is about 34950.1535762005. The cubic root of 1221513235 is about 1068.9713335698.

Adding to 1221513235 its reverse (5323151221), we get a palindrome (6544664456).

The spelling of 1221513235 in words is "one billion, two hundred twenty-one million, five hundred thirteen thousand, two hundred thirty-five".