87019789 has 2 divisors, whose sum is σ = 87019790. Its totient is φ = 87019788.

The previous prime is 87019747. The next prime is 87019811. The reversal of 87019789 is 98791078.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78464164 + 8555625 = 8858^2 + 2925^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87019789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87013789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43509894 + 43509895.

It is an arithmetic number, because the mean of its divisors is an integer number (43509895).

Almost surely, 2^87019789 is an apocalyptic number.

It is an amenable number.

87019789 is a deficient number, since it is larger than the sum of its proper divisors (1).

87019789 is an equidigital number, since it uses as much as digits as its factorization.

87019789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 254016, while the sum is 49.

The square root of 87019789 is about 9328.4397945208. The cubic root of 87019789 is about 443.1383557915.

The spelling of 87019789 in words is "eighty-seven million, nineteen thousand, seven hundred eighty-nine".