85855621 has 2 divisors, whose sum is σ = 85855622. Its totient is φ = 85855620.

The previous prime is 85855603. The next prime is 85855633. The reversal of 85855621 is 12655858.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74390625 + 11464996 = 8625^2 + 3386^2 .

It is a cyclic number.

It is not a de Polignac number, because 85855621 - 2⁷ = 85855493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85855421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42927810 + 42927811.

It is an arithmetic number, because the mean of its divisors is an integer number (42927811).

Almost surely, 2^85855621 is an apocalyptic number.

It is an amenable number.

85855621 is a deficient number, since it is larger than the sum of its proper divisors (1).

85855621 is an equidigital number, since it uses as much as digits as its factorization.

85855621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96000, while the sum is 40.

The square root of 85855621 is about 9265.8308316092. The cubic root of 85855621 is about 441.1533464038.

The spelling of 85855621 in words is "eighty-five million, eight hundred fifty-five thousand, six hundred twenty-one".