15540665540400 has 4500 divisors, whose sum is σ = 77626769513216. Its totient is φ = 2957355878400.

The previous prime is 15540665540333. The next prime is 15540665540401. The reversal of 15540665540400 is 404556604551.

15540665540400 is a `hidden beast` number, since 1 + 5 + 5 + 4 + 0 + 6 + 65 + 540 + 40 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15540665540401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 899 ways as a sum of consecutive naturals, for example, 122367445137 + ... + 122367445263.

Almost surely, 2^{15540665540400} is an apocalyptic number.

15540665540400 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 15540665540400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38813384756608).

15540665540400 is an abundant number, since it is smaller than the sum of its proper divisors (62086103972816).

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

15540665540400 is a wasteful number, since it uses less digits than its factorization.

15540665540400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 220 (or 168 counting only the distinct ones).

The product of its (nonzero) digits is 1440000, while the sum is 45.

The spelling of 15540665540400 in words is "fifteen trillion, five hundred forty billion, six hundred sixty-five million, five hundred forty thousand, four hundred".