87508721 has 8 divisors (see below), whose sum is σ = 91445760. Its totient is φ = 83582752.

The previous prime is 87508717. The next prime is 87508769. The reversal of 87508721 is 12780578.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 87508721 - 2² = 87508717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87508781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16256 + ... + 20958.

It is an arithmetic number, because the mean of its divisors is an integer number (11430720).

Almost surely, 2^87508721 is an apocalyptic number.

It is an amenable number.

87508721 is a deficient number, since it is larger than the sum of its proper divisors (3937039).

87508721 is a wasteful number, since it uses less digits than its factorization.

87508721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5535.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 87508721 is about 9354.6096123783. The cubic root of 87508721 is about 443.9667497352.

It can be divided in two parts, 8750 and 8721, that added together give a palindrome (17471).

The spelling of 87508721 in words is "eighty-seven million, five hundred eight thousand, seven hundred twenty-one".