85621517 has 2 divisors, whose sum is σ = 85621518. Its totient is φ = 85621516.

The previous prime is 85621499. The next prime is 85621559. The reversal of 85621517 is 71512658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 82700836 + 2920681 = 9094^2 + 1709^2 .

It is a cyclic number.

It is not a de Polignac number, because 85621517 - 2²⁰ = 84572941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85621577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42810758 + 42810759.

It is an arithmetic number, because the mean of its divisors is an integer number (42810759).

Almost surely, 2^85621517 is an apocalyptic number.

It is an amenable number.

85621517 is a deficient number, since it is larger than the sum of its proper divisors (1).

85621517 is an equidigital number, since it uses as much as digits as its factorization.

85621517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 16800, while the sum is 35.

The square root of 85621517 is about 9253.1895582010. The cubic root of 85621517 is about 440.7520146013.

The spelling of 85621517 in words is "eighty-five million, six hundred twenty-one thousand, five hundred seventeen".