1221112331545 has 8 divisors (see below), whose sum is σ = 1468043368200. Its totient is φ = 975084151680.

The previous prime is 1221112331513. The next prime is 1221112331603. The reversal of 1221112331545 is 5451332111221.

It can be written as a sum of positive squares in 4 ways, for example, as 16520475024 + 1204591856521 = 128532^2 + 1097539^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221112331545 - 2⁵ = 1221112331513 is a prime.

It is a super-2 number, since 2×1221112331545² (a number of 25 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 225711220 + ... + 225716629.

It is an arithmetic number, because the mean of its divisors is an integer number (183505421025).

Almost surely, 2^{1221112331545} is an apocalyptic number.

It is an amenable number.

1221112331545 is a deficient number, since it is larger than the sum of its proper divisors (246931036655).

1221112331545 is an equidigital number, since it uses as much as digits as its factorization.

1221112331545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 451428395.

The product of its digits is 7200, while the sum is 31.

Adding to 1221112331545 its reverse (5451332111221), we get a palindrome (6672444442766).

The spelling of 1221112331545 in words is "one trillion, two hundred twenty-one billion, one hundred twelve million, three hundred thirty-one thousand, five hundred forty-five".