87931189 has 2 divisors, whose sum is σ = 87931190. Its totient is φ = 87931188.

The previous prime is 87931177. The next prime is 87931211. The reversal of 87931189 is 98113978.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53802225 + 34128964 = 7335^2 + 5842^2 .

It is a cyclic number.

It is not a de Polignac number, because 87931189 - 2¹¹ = 87929141 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87931169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43965594 + 43965595.

It is an arithmetic number, because the mean of its divisors is an integer number (43965595).

Almost surely, 2^87931189 is an apocalyptic number.

It is an amenable number.

87931189 is a deficient number, since it is larger than the sum of its proper divisors (1).

87931189 is an equidigital number, since it uses as much as digits as its factorization.

87931189 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 46.

The square root of 87931189 is about 9377.1631637719. The cubic root of 87931189 is about 444.6800528113.

The spelling of 87931189 in words is "eighty-seven million, nine hundred thirty-one thousand, one hundred eighty-nine".