87639581 has 8 divisors (see below), whose sum is σ = 89549280. Its totient is φ = 85739472.

The previous prime is 87639557. The next prime is 87639583. The reversal of 87639581 is 18593678.

It is a happy number.

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 87639581 - 2¹⁴ = 87623197 is a prime.

It is a super-2 number, since 2×87639581² = 15361392315711122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87639583) 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, 17906 + ... + 22268.

It is an arithmetic number, because the mean of its divisors is an integer number (11193660).

Almost surely, 2^87639581 is an apocalyptic number.

It is an amenable number.

87639581 is a deficient number, since it is larger than the sum of its proper divisors (1909699).

87639581 is a wasteful number, since it uses less digits than its factorization.

87639581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4795.

The product of its digits is 362880, while the sum is 47.

The square root of 87639581 is about 9361.6014121517. The cubic root of 87639581 is about 444.1879412260.

The spelling of 87639581 in words is "eighty-seven million, six hundred thirty-nine thousand, five hundred eighty-one".