1216215570525 has 24 divisors (see below), whose sum is σ = 2011118911104. Its totient is φ = 648548572800.

The previous prime is 1216215570497. The next prime is 1216215570529. The reversal of 1216215570525 is 5250755126121.

It is not a de Polignac number, because 1216215570525 - 2⁶ = 1216215570461 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216215570529) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 754309 + ... + 1732458.

It is an arithmetic number, because the mean of its divisors is an integer number (83796621296).

Almost surely, 2^{1216215570525} is an apocalyptic number.

1216215570525 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1216215570525 is a deficient number, since it is larger than the sum of its proper divisors (794903340579).

1216215570525 is a wasteful number, since it uses less digits than its factorization.

1216215570525 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2493301 (or 2493296 counting only the distinct ones).

The product of its (nonzero) digits is 210000, while the sum is 42.

The spelling of 1216215570525 in words is "one trillion, two hundred sixteen billion, two hundred fifteen million, five hundred seventy thousand, five hundred twenty-five".