1221310015 has 4 divisors (see below), whose sum is σ = 1465572024. Its totient is φ = 977048008.

The previous prime is 1221310001. The next prime is 1221310033. The reversal of 1221310015 is 5100131221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221310015 - 2⁹ = 1221309503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 122130997 + ... + 122131006.

It is an arithmetic number, because the mean of its divisors is an integer number (366393006).

Almost surely, 2^1221310015 is an apocalyptic number.

1221310015 is a deficient number, since it is larger than the sum of its proper divisors (244262009).

1221310015 is an equidigital number, since it uses as much as digits as its factorization.

1221310015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244262008.

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

The square root of 1221310015 is about 34947.2461719089. The cubic root of 1221310015 is about 1068.9120496160.

Adding to 1221310015 its reverse (5100131221), we get a palindrome (6321441236).

The spelling of 1221310015 in words is "one billion, two hundred twenty-one million, three hundred ten thousand, fifteen".