87521784 has 32 divisors (see below), whose sum is σ = 250062720. Its totient is φ = 25006176.

The previous prime is 87521783. The next prime is 87521789. The reversal of 87521784 is 48712578.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87521783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 260314 + ... + 260649.

It is an arithmetic number, because the mean of its divisors is an integer number (7814460).

Almost surely, 2^87521784 is an apocalyptic number.

87521784 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

87521784 is an abundant number, since it is smaller than the sum of its proper divisors (162540936).

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

87521784 is a wasteful number, since it uses less digits than its factorization.

87521784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 520979 (or 520975 counting only the distinct ones).

The product of its digits is 125440, while the sum is 42.

The square root of 87521784 is about 9355.3077982501. The cubic root of 87521784 is about 443.9888399110.

The spelling of 87521784 in words is "eighty-seven million, five hundred twenty-one thousand, seven hundred eighty-four".