87639557 has 2 divisors, whose sum is σ = 87639558. Its totient is φ = 87639556.

The previous prime is 87639553. The next prime is 87639583. The reversal of 87639557 is 75593678.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 87628321 + 11236 = 9361^2 + 106^2 .

It is a cyclic number.

It is not a de Polignac number, because 87639557 - 2² = 87639553 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87639553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43819778 + 43819779.

It is an arithmetic number, because the mean of its divisors is an integer number (43819779).

Almost surely, 2^87639557 is an apocalyptic number.

It is an amenable number.

87639557 is a deficient number, since it is larger than the sum of its proper divisors (1).

87639557 is an equidigital number, since it uses as much as digits as its factorization.

87639557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1587600, while the sum is 50.

The square root of 87639557 is about 9361.6001303196. The cubic root of 87639557 is about 444.1879006792.

The spelling of 87639557 in words is "eighty-seven million, six hundred thirty-nine thousand, five hundred fifty-seven".