85990921 has 2 divisors, whose sum is σ = 85990922. Its totient is φ = 85990920.

The previous prime is 85990909. The next prime is 85990937. The reversal of 85990921 is 12909958.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44890000 + 41100921 = 6700^2 + 6411^2 .

It is a cyclic number.

It is not a de Polignac number, because 85990921 - 2²³ = 77602313 is a prime.

It is not a weakly prime, because it can be changed into another prime (85990901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42995460 + 42995461.

It is an arithmetic number, because the mean of its divisors is an integer number (42995461).

Almost surely, 2^85990921 is an apocalyptic number.

It is an amenable number.

85990921 is a deficient number, since it is larger than the sum of its proper divisors (1).

85990921 is an equidigital number, since it uses as much as digits as its factorization.

85990921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 43.

The square root of 85990921 is about 9273.1289757018. The cubic root of 85990921 is about 441.3849628483.

The spelling of 85990921 in words is "eighty-five million, nine hundred ninety thousand, nine hundred twenty-one".