85651921 has 2 divisors, whose sum is σ = 85651922. Its totient is φ = 85651920.

The previous prime is 85651837. The next prime is 85651957. The reversal of 85651921 is 12915658.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 82083600 + 3568321 = 9060^2 + 1889^2 .

It is a cyclic number.

It is not a de Polignac number, because 85651921 - 2⁹ = 85651409 is a prime.

It is not a weakly prime, because it can be changed into another prime (85651961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42825960 + 42825961.

It is an arithmetic number, because the mean of its divisors is an integer number (42825961).

Almost surely, 2^85651921 is an apocalyptic number.

It is an amenable number.

85651921 is a deficient number, since it is larger than the sum of its proper divisors (1).

85651921 is an equidigital number, since it uses as much as digits as its factorization.

85651921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 37.

The square root of 85651921 is about 9254.8323053419. The cubic root of 85651921 is about 440.8041784298.

The spelling of 85651921 in words is "eighty-five million, six hundred fifty-one thousand, nine hundred twenty-one".