1213387805544 has 48 divisors (see below), whose sum is σ = 3061555549920. Its totient is φ = 400751841600.

The previous prime is 1213387805479. The next prime is 1213387805551. The reversal of 1213387805544 is 4455087833121.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1842532 + ... + 2412819.

It is an arithmetic number, because the mean of its divisors is an integer number (63782407290).

Almost surely, 2^{1213387805544} is an apocalyptic number.

It is an amenable number.

1213387805544 is an abundant number, since it is smaller than the sum of its proper divisors (1848167744376).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1213387805544 is a wasteful number, since it uses less digits than its factorization.

1213387805544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4255578 (or 4255465 counting only the distinct ones).

The product of its (nonzero) digits is 3225600, while the sum is 51.

The spelling of 1213387805544 in words is "one trillion, two hundred thirteen billion, three hundred eighty-seven million, eight hundred five thousand, five hundred forty-four".