85777921 has 2 divisors, whose sum is σ = 85777922. Its totient is φ = 85777920.

The previous prime is 85777907. The next prime is 85777943. The reversal of 85777921 is 12977758.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55130625 + 30647296 = 7425^2 + 5536^2 .

It is a cyclic number.

It is not a de Polignac number, because 85777921 - 2¹³ = 85769729 is a prime.

It is not a weakly prime, because it can be changed into another prime (85774921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42888960 + 42888961.

It is an arithmetic number, because the mean of its divisors is an integer number (42888961).

Almost surely, 2^85777921 is an apocalyptic number.

It is an amenable number.

85777921 is a deficient number, since it is larger than the sum of its proper divisors (1).

85777921 is an equidigital number, since it uses as much as digits as its factorization.

85777921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 246960, while the sum is 46.

The square root of 85777921 is about 9261.6370583175. The cubic root of 85777921 is about 441.0202238417.

The spelling of 85777921 in words is "eighty-five million, seven hundred seventy-seven thousand, nine hundred twenty-one".