87287721 has 8 divisors (see below), whose sum is σ = 119090400. Its totient is φ = 56838432.

The previous prime is 87287713. The next prime is 87287747. The reversal of 87287721 is 12778278.

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

It is not a de Polignac number, because 87287721 - 2³ = 87287713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (87287771) 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, 338196 + ... + 338453.

It is an arithmetic number, because the mean of its divisors is an integer number (14886300).

Almost surely, 2^87287721 is an apocalyptic number.

It is an amenable number.

87287721 is a deficient number, since it is larger than the sum of its proper divisors (31802679).

87287721 is a wasteful number, since it uses less digits than its factorization.

87287721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676695.

The product of its digits is 87808, while the sum is 42.

The square root of 87287721 is about 9342.7897867821. The cubic root of 87287721 is about 443.5926942000.

The spelling of 87287721 in words is "eighty-seven million, two hundred eighty-seven thousand, seven hundred twenty-one".