1551231553440 has 192 divisors, whose sum is σ = 5056760016000. Its totient is φ = 399408721920.

The previous prime is 1551231553429. The next prime is 1551231553483. The reversal of 1551231553440 is 443551321551.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1993186 + ... + 2659934.

It is an arithmetic number, because the mean of its divisors is an integer number (26337291750).

Almost surely, 2^{1551231553440} is an apocalyptic number.

1551231553440 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 1551231553440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2528380008000).

1551231553440 is an abundant number, since it is smaller than the sum of its proper divisors (3505528462560).

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

1551231553440 is a wasteful number, since it uses less digits than its factorization.

1551231553440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 666935 (or 666927 counting only the distinct ones).

The product of its (nonzero) digits is 180000, while the sum is 39.

Adding to 1551231553440 its reverse (443551321551), we get a palindrome (1994782874991).

The spelling of 1551231553440 in words is "one trillion, five hundred fifty-one billion, two hundred thirty-one million, five hundred fifty-three thousand, four hundred forty".