1243545121 has 32 divisors (see below), whose sum is σ = 1624347648. Its totient is φ = 923857920.

The previous prime is 1243545109. The next prime is 1243545131. The reversal of 1243545121 is 1215453421.

It is a cyclic number.

It is not a de Polignac number, because 1243545121 - 2¹⁹ = 1243020833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1243545121.

It is not an unprimeable number, because it can be changed into a prime (1243545131) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1009576 + ... + 1010806.

It is an arithmetic number, because the mean of its divisors is an integer number (50760864).

Almost surely, 2^1243545121 is an apocalyptic number.

It is an amenable number.

1243545121 is a deficient number, since it is larger than the sum of its proper divisors (380802527).

1243545121 is a wasteful number, since it uses less digits than its factorization.

1243545121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1921.

The product of its digits is 4800, while the sum is 28.

The square root of 1243545121 is about 35263.9351320864. The cubic root of 1243545121 is about 1075.3599288001.

Adding to 1243545121 its reverse (1215453421), we get a palindrome (2458998542).

The spelling of 1243545121 in words is "one billion, two hundred forty-three million, five hundred forty-five thousand, one hundred twenty-one".