85709021 has 4 divisors (see below), whose sum is σ = 85766112. Its totient is φ = 85651932.

The previous prime is 85709011. The next prime is 85709027. The reversal of 85709021 is 12090758.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 85709021 - 2¹⁴ = 85692637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85709027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26231 + ... + 29316.

It is an arithmetic number, because the mean of its divisors is an integer number (21441528).

Almost surely, 2^85709021 is an apocalyptic number.

It is an amenable number.

85709021 is a deficient number, since it is larger than the sum of its proper divisors (57091).

85709021 is a wasteful number, since it uses less digits than its factorization.

85709021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57090.

The product of its (nonzero) digits is 5040, while the sum is 32.

The square root of 85709021 is about 9257.9166662916. The cubic root of 85709021 is about 440.9021109579.

Adding to 85709021 its reverse (12090758), we get a palindrome (97799779).

The spelling of 85709021 in words is "eighty-five million, seven hundred nine thousand, twenty-one".