87311520 has 120 divisors (see below), whose sum is σ = 308182644. Its totient is φ = 23279616.

The previous prime is 87311513. The next prime is 87311533. The reversal of 87311520 is 2511378.

It can be written as a sum of positive squares in 2 ways, for example, as 86936976 + 374544 = 9324^2 + 612^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9592 + ... + 16328.

Almost surely, 2^87311520 is an apocalyptic number.

87311520 is a gapful number since it is divisible by the number (80) 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 87311520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154091322).

87311520 is an abundant number, since it is smaller than the sum of its proper divisors (220871124).

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

87311520 is a wasteful number, since it uses less digits than its factorization.

87311520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6764 (or 6747 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 87311520 is about 9344.0633559496. The cubic root of 87311520 is about 443.6330057241.

Adding to 87311520 its reverse (2511378), we get a palindrome (89822898).

The spelling of 87311520 in words is "eighty-seven million, three hundred eleven thousand, five hundred twenty".