85909639 has 4 divisors (see below), whose sum is σ = 86436856. Its totient is φ = 85382424.

The previous prime is 85909633. The next prime is 85909667. The reversal of 85909639 is 93690958.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 85909639 - 2¹⁹ = 85385351 is a prime.

It is a super-2 number, since 2×85909639² = 14760932146220642, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85909592 and 85909601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85909633) 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 3 ways as a sum of consecutive naturals, for example, 263364 + ... + 263689.

It is an arithmetic number, because the mean of its divisors is an integer number (21609214).

Almost surely, 2^85909639 is an apocalyptic number.

85909639 is a deficient number, since it is larger than the sum of its proper divisors (527217).

85909639 is a wasteful number, since it uses less digits than its factorization.

85909639 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527216.

The product of its (nonzero) digits is 524880, while the sum is 49.

The square root of 85909639 is about 9268.7452764654. The cubic root of 85909639 is about 441.2458475321.

The spelling of 85909639 in words is "eighty-five million, nine hundred nine thousand, six hundred thirty-nine".