1221203400215 has 16 divisors (see below), whose sum is σ = 1466341845696. Its totient is φ = 976364390400.

The previous prime is 1221203400203. The next prime is 1221203400251. The reversal of 1221203400215 is 5120043021221.

It is not a de Polignac number, because 1221203400215 - 2⁸ = 1221203399959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112433885 + ... + 112444745.

It is an arithmetic number, because the mean of its divisors is an integer number (91646365356).

Almost surely, 2^{1221203400215} is an apocalyptic number.

1221203400215 is a deficient number, since it is larger than the sum of its proper divisors (245138445481).

1221203400215 is a wasteful number, since it uses less digits than its factorization.

1221203400215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22570.

The product of its (nonzero) digits is 960, while the sum is 23.

Adding to 1221203400215 its reverse (5120043021221), we get a palindrome (6341246421436).

The spelling of 1221203400215 in words is "one trillion, two hundred twenty-one billion, two hundred three million, four hundred thousand, two hundred fifteen".