87173931 has 8 divisors (see below), whose sum is σ = 125172880. Its totient is φ = 53645472.

The previous prime is 87173929. The next prime is 87173951. The reversal of 87173931 is 13937178.

It is a happy number.

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

It is not a de Polignac number, because 87173931 - 2¹ = 87173929 is a prime.

It is a super-2 number, since 2×87173931² = 15198588491985522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39), and also a Moran number because the ratio is a prime number: 2235229 = 87173931 / (8 + 7 + 1 + 7 + 3 + 9 + 3 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 87173931.

It is not an unprimeable number, because it can be changed into a prime (87173951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1117576 + ... + 1117653.

It is an arithmetic number, because the mean of its divisors is an integer number (15646610).

Almost surely, 2^87173931 is an apocalyptic number.

87173931 is a deficient number, since it is larger than the sum of its proper divisors (37998949).

87173931 is a wasteful number, since it uses less digits than its factorization.

87173931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2235245.

The product of its digits is 31752, while the sum is 39.

The square root of 87173931 is about 9336.6980780145. The cubic root of 87173931 is about 443.3998516405.

The spelling of 87173931 in words is "eighty-seven million, one hundred seventy-three thousand, nine hundred thirty-one".