1221032431545 has 128 divisors (see below), whose sum is σ = 2112749775360. Its totient is φ = 601047982080.

The previous prime is 1221032431511. The next prime is 1221032431571. The reversal of 1221032431545 is 5451342301221.

It is not a de Polignac number, because 1221032431545 - 2²² = 1221028237241 is a prime.

It is a super-2 number, since 2×1221032431545² (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 127 ways as a sum of consecutive naturals, for example, 139685875 + ... + 139694615.

It is an arithmetic number, because the mean of its divisors is an integer number (16505857620).

Almost surely, 2^{1221032431545} is an apocalyptic number.

1221032431545 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1221032431545 is a deficient number, since it is larger than the sum of its proper divisors (891717343815).

1221032431545 is a wasteful number, since it uses less digits than its factorization.

1221032431545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8987.

The product of its (nonzero) digits is 28800, while the sum is 33.

Adding to 1221032431545 its reverse (5451342301221), we get a palindrome (6672374732766).

The spelling of 1221032431545 in words is "one trillion, two hundred twenty-one billion, thirty-two million, four hundred thirty-one thousand, five hundred forty-five".