85708921 has 2 divisors, whose sum is σ = 85708922. Its totient is φ = 85708920.

The previous prime is 85708919. The next prime is 85708927. The reversal of 85708921 is 12980758.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 58293225 + 27415696 = 7635^2 + 5236^2 .

It is a cyclic number.

It is not a de Polignac number, because 85708921 - 2¹ = 85708919 is a prime.

Together with 85708919, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (85708927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42854460 + 42854461.

It is an arithmetic number, because the mean of its divisors is an integer number (42854461).

Almost surely, 2^85708921 is an apocalyptic number.

It is an amenable number.

85708921 is a deficient number, since it is larger than the sum of its proper divisors (1).

85708921 is an equidigital number, since it uses as much as digits as its factorization.

85708921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 40.

The square root of 85708921 is about 9257.9112655069. The cubic root of 85708921 is about 440.9019394854.

The spelling of 85708921 in words is "eighty-five million, seven hundred eight thousand, nine hundred twenty-one".