87639193 has 4 divisors (see below), whose sum is σ = 88084260. Its totient is φ = 87194128.

The previous prime is 87639187. The next prime is 87639217. The reversal of 87639193 is 39193678.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 59474944 + 28164249 = 7712^2 + 5307^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87639193 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87639113) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 222238 + ... + 222631.

It is an arithmetic number, because the mean of its divisors is an integer number (22021065).

Almost surely, 2^87639193 is an apocalyptic number.

It is an amenable number.

87639193 is a deficient number, since it is larger than the sum of its proper divisors (445067).

87639193 is a wasteful number, since it uses less digits than its factorization.

87639193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 445066.

The product of its digits is 244944, while the sum is 46.

The square root of 87639193 is about 9361.5806891785. The cubic root of 87639193 is about 444.1872857186.

It can be divided in two parts, 8763 and 9193, that added together give a square (17956 = 134²).

The spelling of 87639193 in words is "eighty-seven million, six hundred thirty-nine thousand, one hundred ninety-three".