1221602312215 has 4 divisors (see below), whose sum is σ = 1465922774664. Its totient is φ = 977281849768.

The previous prime is 1221602312213. The next prime is 1221602312261. The reversal of 1221602312215 is 5122132061221.

It is a happy number.

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 1221602312215 - 2¹ = 1221602312213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221602312213) 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, 122160231217 + ... + 122160231226.

It is an arithmetic number, because the mean of its divisors is an integer number (366480693666).

Almost surely, 2^{1221602312215} is an apocalyptic number.

1221602312215 is a deficient number, since it is larger than the sum of its proper divisors (244320462449).

1221602312215 is an equidigital number, since it uses as much as digits as its factorization.

1221602312215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244320462448.

The product of its (nonzero) digits is 2880, while the sum is 28.

Adding to 1221602312215 its reverse (5122132061221), we get a palindrome (6343734373436).

The spelling of 1221602312215 in words is "one trillion, two hundred twenty-one billion, six hundred two million, three hundred twelve thousand, two hundred fifteen".