1213315521 has 48 divisors (see below), whose sum is σ = 1820206080. Its totient is φ = 718194400.

The previous prime is 1213315511. The next prime is 1213315561. The reversal of 1213315521 is 1255133121.

It is not a de Polignac number, because 1213315521 - 2⁶ = 1213315457 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1213315491 and 1213315500.

It is not an unprimeable number, because it can be changed into a prime (1213315511) 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 47 ways as a sum of consecutive naturals, for example, 4613236 + ... + 4613498.

It is an arithmetic number, because the mean of its divisors is an integer number (37920960).

Almost surely, 2^1213315521 is an apocalyptic number.

1213315521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1213315521 is a deficient number, since it is larger than the sum of its proper divisors (606890559).

1213315521 is a wasteful number, since it uses less digits than its factorization.

1213315521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 538 (or 527 counting only the distinct ones).

The product of its digits is 900, while the sum is 24.

The square root of 1213315521 is about 34832.6789236774. The cubic root of 1213315521 is about 1066.5746347138.

Adding to 1213315521 its reverse (1255133121), we get a palindrome (2468448642).

The spelling of 1213315521 in words is "one billion, two hundred thirteen million, three hundred fifteen thousand, five hundred twenty-one".