85723939409 has 2 divisors, whose sum is σ = 85723939410. Its totient is φ = 85723939408.

The previous prime is 85723939387. The next prime is 85723939417. The reversal of 85723939409 is 90493932758.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80897580625 + 4826358784 = 284425^2 + 69472^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85723939409 is a prime.

It is not a weakly prime, because it can be changed into another prime (85723939489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42861969704 + 42861969705.

It is an arithmetic number, because the mean of its divisors is an integer number (42861969705).

Almost surely, 2^85723939409 is an apocalyptic number.

It is an amenable number.

85723939409 is a deficient number, since it is larger than the sum of its proper divisors (1).

85723939409 is an equidigital number, since it uses as much as digits as its factorization.

85723939409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14696640, while the sum is 59.

The spelling of 85723939409 in words is "eighty-five billion, seven hundred twenty-three million, nine hundred thirty-nine thousand, four hundred nine".