87639845 has 8 divisors (see below), whose sum is σ = 111354264. Its totient is φ = 65987584.

The previous prime is 87639829. The next prime is 87639847. The reversal of 87639845 is 54893678.

It can be written as a sum of positive squares in 4 ways, for example, as 23367556 + 64272289 = 4834^2 + 8017^2 .

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 87639845 - 2⁴ = 87639829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 87639793 and 87639802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87639847) 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, 515444 + ... + 515613.

It is an arithmetic number, because the mean of its divisors is an integer number (13919283).

Almost surely, 2^87639845 is an apocalyptic number.

87639845 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

87639845 is a deficient number, since it is larger than the sum of its proper divisors (23714419).

87639845 is a wasteful number, since it uses less digits than its factorization.

87639845 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1031079.

The product of its digits is 1451520, while the sum is 50.

The square root of 87639845 is about 9361.6155122927. The cubic root of 87639845 is about 444.1883872402.

The spelling of 87639845 in words is "eighty-seven million, six hundred thirty-nine thousand, eight hundred forty-five".