215304321520 has 80 divisors (see below), whose sum is σ = 506428524000. Its totient is φ = 85116821504.

The previous prime is 215304321367. The next prime is 215304321523. The reversal of 215304321520 is 25123403512.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×215304321520² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215304321523) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20920536 + ... + 20930824.

It is an arithmetic number, because the mean of its divisors is an integer number (6330356550).

Almost surely, 2^215304321520 is an apocalyptic number.

215304321520 is a gapful number since it is divisible by the number (20) 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 215304321520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (253214262000).

215304321520 is an abundant number, since it is smaller than the sum of its proper divisors (291124202480).

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

215304321520 is a wasteful number, since it uses less digits than its factorization.

215304321520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13330 (or 13324 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The spelling of 215304321520 in words is "two hundred fifteen billion, three hundred four million, three hundred twenty-one thousand, five hundred twenty".