1213387805545 has 4 divisors (see below), whose sum is σ = 1456065366660. Its totient is φ = 970710244432.

The previous prime is 1213387805479. The next prime is 1213387805551. The reversal of 1213387805545 is 5455087833121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 417702397401 + 795685408144 = 646299^2 + 892012^2 .

It is a cyclic number.

It is not a de Polignac number, because 1213387805545 - 2³⁵ = 1179028067177 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1213387805492 and 1213387805501.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 121338780550 + ... + 121338780559.

It is an arithmetic number, because the mean of its divisors is an integer number (364016341665).

Almost surely, 2^{1213387805545} is an apocalyptic number.

It is an amenable number.

1213387805545 is a deficient number, since it is larger than the sum of its proper divisors (242677561115).

1213387805545 is an equidigital number, since it uses as much as digits as its factorization.

1213387805545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 242677561114.

The product of its (nonzero) digits is 4032000, while the sum is 52.

The spelling of 1213387805545 in words is "one trillion, two hundred thirteen billion, three hundred eighty-seven million, eight hundred five thousand, five hundred forty-five".