85431977 has 2 divisors, whose sum is σ = 85431978. Its totient is φ = 85431976.

The previous prime is 85431889. The next prime is 85432019. The reversal of 85431977 is 77913458.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75672601 + 9759376 = 8699^2 + 3124^2 .

It is a cyclic number.

It is not a de Polignac number, because 85431977 - 2²⁶ = 18323113 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (85431377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42715988 + 42715989.

It is an arithmetic number, because the mean of its divisors is an integer number (42715989).

Almost surely, 2^85431977 is an apocalyptic number.

It is an amenable number.

85431977 is a deficient number, since it is larger than the sum of its proper divisors (1).

85431977 is an equidigital number, since it uses as much as digits as its factorization.

85431977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 211680, while the sum is 44.

The square root of 85431977 is about 9242.9420099879. The cubic root of 85431977 is about 440.4265440115.

The spelling of 85431977 in words is "eighty-five million, four hundred thirty-one thousand, nine hundred seventy-seven".