15521566794240 has 1280 divisors, whose sum is σ = 56237200588800. Its totient is φ = 3626178969600.

The previous prime is 15521566794233. The next prime is 15521566794277. The reversal of 15521566794240 is 4249766512551.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (1280).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 46892950875 + ... + 46892951205.

It is an arithmetic number, because the mean of its divisors is an integer number (43935312960).

Almost surely, 2^{15521566794240} is an apocalyptic number.

15521566794240 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 15521566794240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28118600294400).

15521566794240 is an abundant number, since it is smaller than the sum of its proper divisors (40715633794560).

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

15521566794240 is a wasteful number, since it uses less digits than its factorization.

15521566794240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 633 counting only the distinct ones).

The product of its (nonzero) digits is 18144000, while the sum is 57.

The spelling of 15521566794240 in words is "fifteen trillion, five hundred twenty-one billion, five hundred sixty-six million, seven hundred ninety-four thousand, two hundred forty".