1231511340545 has 16 divisors (see below), whose sum is σ = 1520422053840. Its totient is φ = 956897040384.

The previous prime is 1231511340533. The next prime is 1231511340551. The reversal of 1231511340545 is 5450431151321.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 581002816 + 1230930337729 = 24104^2 + 1109473^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231511340545 - 2⁴ = 1231511340529 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5744312 + ... + 5954841.

It is an arithmetic number, because the mean of its divisors is an integer number (95026378365).

Almost surely, 2^{1231511340545} is an apocalyptic number.

It is an amenable number.

1231511340545 is a deficient number, since it is larger than the sum of its proper divisors (288910713295).

1231511340545 is a wasteful number, since it uses less digits than its factorization.

1231511340545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11699764.

The product of its (nonzero) digits is 36000, while the sum is 35.

Adding to 1231511340545 its reverse (5450431151321), we get a palindrome (6681942491866).

The spelling of 1231511340545 in words is "one trillion, two hundred thirty-one billion, five hundred eleven million, three hundred forty thousand, five hundred forty-five".