1221105545 has 16 divisors (see below), whose sum is σ = 1617803712. Its totient is φ = 877373760.

The previous prime is 1221105541. The next prime is 1221105569. The reversal of 1221105545 is 5455011221.

It is not a de Polignac number, because 1221105545 - 2² = 1221105541 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221105541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 129182 + ... + 138311.

It is an arithmetic number, because the mean of its divisors is an integer number (101112732).

Almost surely, 2^1221105545 is an apocalyptic number.

It is an amenable number.

1221105545 is a deficient number, since it is larger than the sum of its proper divisors (396698167).

1221105545 is a wasteful number, since it uses less digits than its factorization.

1221105545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267592.

The product of its (nonzero) digits is 2000, while the sum is 26.

The square root of 1221105545 is about 34944.3206401269. The cubic root of 1221105545 is about 1068.8523943709.

Adding to 1221105545 its reverse (5455011221), we get a palindrome (6676116766).

The spelling of 1221105545 in words is "one billion, two hundred twenty-one million, one hundred five thousand, five hundred forty-five".