1225111243521 has 16 divisors (see below), whose sum is σ = 1782776691648. Its totient is φ = 742159704000.

The previous prime is 1225111243513. The next prime is 1225111243529. The reversal of 1225111243521 is 1253421115221.

It is an interprime number because it is at equal distance from previous prime (1225111243513) and next prime (1225111243529).

It is not a de Polignac number, because 1225111243521 - 2³ = 1225111243513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1225111243529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8224030 + ... + 8371671.

It is an arithmetic number, because the mean of its divisors is an integer number (111423543228).

Almost surely, 2^{1225111243521} is an apocalyptic number.

1225111243521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1225111243521 is a deficient number, since it is larger than the sum of its proper divisors (557665448127).

1225111243521 is a wasteful number, since it uses less digits than its factorization.

1225111243521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16597952.

The product of its digits is 4800, while the sum is 30.

Adding to 1225111243521 its reverse (1253421115221), we get a palindrome (2478532358742).

The spelling of 1225111243521 in words is "one trillion, two hundred twenty-five billion, one hundred eleven million, two hundred forty-three thousand, five hundred twenty-one".