85019191861 has 4 divisors (see below), whose sum is σ = 90020320812. Its totient is φ = 80018062912.

The previous prime is 85019191849. The next prime is 85019191951. The reversal of 85019191861 is 16819191058.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36359243761 + 48659948100 = 190681^2 + 220590^2 .

It is a cyclic number.

It is not a de Polignac number, because 85019191861 - 2⁹ = 85019191349 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85019191811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2500564450 + ... + 2500564483.

It is an arithmetic number, because the mean of its divisors is an integer number (22505080203).

Almost surely, 2^85019191861 is an apocalyptic number.

It is an amenable number.

85019191861 is a deficient number, since it is larger than the sum of its proper divisors (5001128951).

85019191861 is a wasteful number, since it uses less digits than its factorization.

85019191861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5001128950.

The product of its (nonzero) digits is 155520, while the sum is 49.

The spelling of 85019191861 in words is "eighty-five billion, nineteen million, one hundred ninety-one thousand, eight hundred sixty-one".