1221105551215 has 48 divisors (see below), whose sum is σ = 1686620726784. Its totient is φ = 846460359360.

The previous prime is 1221105551209. The next prime is 1221105551221. The reversal of 1221105551215 is 5121555011221.

It is an interprime number because it is at equal distance from previous prime (1221105551209) and next prime (1221105551221).

It is a de Polignac number, because none of the positive numbers 2^k-1221105551215 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 47 ways as a sum of consecutive naturals, for example, 3782902 + ... + 4092988.

It is an arithmetic number, because the mean of its divisors is an integer number (35137931808).

Almost surely, 2^{1221105551215} is an apocalyptic number.

1221105551215 is a deficient number, since it is larger than the sum of its proper divisors (465515175569).

1221105551215 is a wasteful number, since it uses less digits than its factorization.

1221105551215 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310420 (or 310409 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 31.

The spelling of 1221105551215 in words is "one trillion, two hundred twenty-one billion, one hundred five million, five hundred fifty-one thousand, two hundred fifteen".