1221147545 has 16 divisors (see below), whose sum is σ = 1480550400. Its totient is φ = 966841344.

The previous prime is 1221147541. The next prime is 1221147607. The reversal of 1221147545 is 5457411221.

It is a cyclic number.

It is not a de Polignac number, because 1221147545 - 2² = 1221147541 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1221147541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 282974 + ... + 287256.

It is an arithmetic number, because the mean of its divisors is an integer number (92534400).

Almost surely, 2^1221147545 is an apocalyptic number.

It is an amenable number.

1221147545 is a deficient number, since it is larger than the sum of its proper divisors (259402855).

1221147545 is a wasteful number, since it uses less digits than its factorization.

1221147545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4864.

The product of its digits is 11200, while the sum is 32.

The square root of 1221147545 is about 34944.9215909837. The cubic root of 1221147545 is about 1068.8646486449.

Adding to 1221147545 its reverse (5457411221), we get a palindrome (6678558766).

The spelling of 1221147545 in words is "one billion, two hundred twenty-one million, one hundred forty-seven thousand, five hundred forty-five".