15550891161840 has 720 divisors, whose sum is σ = 56015719014528. Its totient is φ = 4008853596672.

The previous prime is 15550891161823. The next prime is 15550891161851. The reversal of 15550891161840 is 4816119805551.

15550891161840 is a `hidden beast` number, since 1 + 5 + 5 + 5 + 0 + 8 + 9 + 11 + 618 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 3564263499 + ... + 3564267861.

Almost surely, 2^{15550891161840} is an apocalyptic number.

15550891161840 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 15550891161840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28007859507264).

15550891161840 is an abundant number, since it is smaller than the sum of its proper divisors (40464827852688).

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

15550891161840 is an equidigital number, since it uses as much as digits as its factorization.

15550891161840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4568 (or 4503 counting only the distinct ones).

The product of its (nonzero) digits is 1728000, while the sum is 54.

The spelling of 15550891161840 in words is "fifteen trillion, five hundred fifty billion, eight hundred ninety-one million, one hundred sixty-one thousand, eight hundred forty".