1221005113 has 4 divisors (see below), whose sum is σ = 1285268560. Its totient is φ = 1156741668.

The previous prime is 1221005063. The next prime is 1221005173. The reversal of 1221005113 is 3115001221.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 3115001221 = 16253 ⋅191657.

It is a cyclic number.

It is not a de Polignac number, because 1221005113 - 2¹³ = 1220996921 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221005173) 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, 32131695 + ... + 32131732.

It is an arithmetic number, because the mean of its divisors is an integer number (321317140).

Almost surely, 2^1221005113 is an apocalyptic number.

It is an amenable number.

1221005113 is a deficient number, since it is larger than the sum of its proper divisors (64263447).

1221005113 is an equidigital number, since it uses as much as digits as its factorization.

1221005113 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64263446.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 1221005113 is about 34942.8835816393. The cubic root of 1221005113 is about 1068.8230903446.

Adding to 1221005113 its reverse (3115001221), we get a palindrome (4336006334).

The spelling of 1221005113 in words is "one billion, two hundred twenty-one million, five thousand, one hundred thirteen".