1551111455440 has 80 divisors (see below), whose sum is σ = 3822108137280. Its totient is φ = 583391692800.

The previous prime is 1551111455347. The next prime is 1551111455461. The reversal of 1551111455440 is 445541111551.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 1551111455440.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 886771 + ... + 1971949.

It is an arithmetic number, because the mean of its divisors is an integer number (47776351716).

Almost surely, 2^{1551111455440} is an apocalyptic number.

1551111455440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1551111455440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1911054068640).

1551111455440 is an abundant number, since it is smaller than the sum of its proper divisors (2270996681840).

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

1551111455440 is a wasteful number, since it uses less digits than its factorization.

1551111455440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1086260 (or 1086254 counting only the distinct ones).

The product of its (nonzero) digits is 40000, while the sum is 37.

Adding to 1551111455440 its reverse (445541111551), we get a palindrome (1996652566991).

The spelling of 1551111455440 in words is "one trillion, five hundred fifty-one billion, one hundred eleven million, four hundred fifty-five thousand, four hundred forty".