85128919 has 2 divisors, whose sum is σ = 85128920. Its totient is φ = 85128918.

The previous prime is 85128913. The next prime is 85128943. The reversal of 85128919 is 91982158.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 85128919 - 2⁵ = 85128887 is a prime.

It is a super-2 number, since 2×85128919² = 14493865700217122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85128913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42564459 + 42564460.

It is an arithmetic number, because the mean of its divisors is an integer number (42564460).

Almost surely, 2^85128919 is an apocalyptic number.

85128919 is a deficient number, since it is larger than the sum of its proper divisors (1).

85128919 is an equidigital number, since it uses as much as digits as its factorization.

85128919 is an evil number, because the sum of its binary digits is even.

The product of its digits is 51840, while the sum is 43.

The square root of 85128919 is about 9226.5334226892. The cubic root of 85128919 is about 439.9051431194.

The spelling of 85128919 in words is "eighty-five million, one hundred twenty-eight thousand, nine hundred nineteen".