1521320220416 has 72 divisors (see below), whose sum is σ = 3110254398720. Its totient is φ = 742328351744.

The previous prime is 1521320220337. The next prime is 1521320220439. The reversal of 1521320220416 is 6140220231251.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3992915 + ... + 4357293.

It is an arithmetic number, because the mean of its divisors is an integer number (43197977760).

Almost surely, 2^{1521320220416} is an apocalyptic number.

1521320220416 is a gapful number since it is divisible by the number (16) 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 1521320220416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1555127199360).

1521320220416 is an abundant number, since it is smaller than the sum of its proper divisors (1588934178304).

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

1521320220416 is an equidigital number, since it uses as much as digits as its factorization.

1521320220416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364789 (or 364775 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 29.

Adding to 1521320220416 its reverse (6140220231251), we get a palindrome (7661540451667).

The spelling of 1521320220416 in words is "one trillion, five hundred twenty-one billion, three hundred twenty million, two hundred twenty thousand, four hundred sixteen".