85613509 has 2 divisors, whose sum is σ = 85613510. Its totient is φ = 85613508.

The previous prime is 85613503. The next prime is 85613551. The reversal of 85613509 is 90531658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78269409 + 7344100 = 8847^2 + 2710^2 .

It is a cyclic number.

It is not a de Polignac number, because 85613509 - 2³ = 85613501 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85613501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42806754 + 42806755.

It is an arithmetic number, because the mean of its divisors is an integer number (42806755).

Almost surely, 2^85613509 is an apocalyptic number.

It is an amenable number.

85613509 is a deficient number, since it is larger than the sum of its proper divisors (1).

85613509 is an equidigital number, since it uses as much as digits as its factorization.

85613509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 37.

The square root of 85613509 is about 9252.7568324257. The cubic root of 85613509 is about 440.7382733040.

It can be divided in two parts, 856 and 13509, that added together give a triangular number (14365 = T₁₆₉).

The spelling of 85613509 in words is "eighty-five million, six hundred thirteen thousand, five hundred nine".