85578431 has 2 divisors, whose sum is σ = 85578432. Its totient is φ = 85578430.

The previous prime is 85578421. The next prime is 85578457. The reversal of 85578431 is 13487558.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85578431 - 2¹⁰ = 85577407 is a prime.

It is a super-4 number, since 4×85578431⁴ (a number of 33 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85578421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42789215 + 42789216.

It is an arithmetic number, because the mean of its divisors is an integer number (42789216).

Almost surely, 2^85578431 is an apocalyptic number.

85578431 is a deficient number, since it is larger than the sum of its proper divisors (1).

85578431 is an equidigital number, since it uses as much as digits as its factorization.

85578431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 134400, while the sum is 41.

The square root of 85578431 is about 9250.8610950549. The cubic root of 85578431 is about 440.6780712428.

The spelling of 85578431 in words is "eighty-five million, five hundred seventy-eight thousand, four hundred thirty-one".