85459781987 has 2 divisors, whose sum is σ = 85459781988. Its totient is φ = 85459781986.

The previous prime is 85459781977. The next prime is 85459781999. The reversal of 85459781987 is 78918795458.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85459781987 - 2²⁰ = 85458733411 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 85459781987.

It is not a weakly prime, because it can be changed into another prime (85459781917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42729890993 + 42729890994.

It is an arithmetic number, because the mean of its divisors is an integer number (42729890994).

Almost surely, 2^85459781987 is an apocalyptic number.

85459781987 is a deficient number, since it is larger than the sum of its proper divisors (1).

85459781987 is an equidigital number, since it uses as much as digits as its factorization.

85459781987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 203212800, while the sum is 71.

The spelling of 85459781987 in words is "eighty-five billion, four hundred fifty-nine million, seven hundred eighty-one thousand, nine hundred eighty-seven".