87981321 has 16 divisors (see below), whose sum is σ = 120121344. Its totient is φ = 57254544.

The previous prime is 87981319. The next prime is 87981347. The reversal of 87981321 is 12318978.

It is not a de Polignac number, because 87981321 - 2¹ = 87981319 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 87981321.

It is not an unprimeable number, because it can be changed into a prime (87981521) 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, 82236 + ... + 83298.

It is an arithmetic number, because the mean of its divisors is an integer number (7507584).

Almost surely, 2^87981321 is an apocalyptic number.

It is an amenable number.

87981321 is a deficient number, since it is larger than the sum of its proper divisors (32140023).

87981321 is a wasteful number, since it uses less digits than its factorization.

87981321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1700.

The product of its digits is 24192, while the sum is 39.

The square root of 87981321 is about 9379.8358727645. The cubic root of 87981321 is about 444.7645448838.

The spelling of 87981321 in words is "eighty-seven million, nine hundred eighty-one thousand, three hundred twenty-one".