85491604191889 has 9 divisors (see below), whose sum is σ = 99449492411451. Its totient is φ = 73278462401760.

The previous prime is 85491604191887. The next prime is 85491604191913. The reversal of 85491604191889 is 98819140619458.

The square root of 85491604191889 is 9246167.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 61593976401489 + 23897627790400 = 7848183^2 + 4888520^2 .

It is not a de Polignac number, because 85491604191889 - 2¹ = 85491604191887 is a prime.

It is a super-2 number, since 2×85491604191889² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (85491604191887) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 64062729 + ... + 65383609.

Almost surely, 2^{85491604191889} is an apocalyptic number.

85491604191889 is the 9246167-th square number.

85491604191889 is the 4623084-th centered octagonal number.

It is an amenable number.

85491604191889 is a deficient number, since it is larger than the sum of its proper divisors (13957888219562).

85491604191889 is an frugal number, since it uses more digits than its factorization.

85491604191889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2641776 (or 1320888 counting only the distinct ones).

The product of its (nonzero) digits is 179159040, while the sum is 73.

The spelling of 85491604191889 in words is "eighty-five trillion, four hundred ninety-one billion, six hundred four million, one hundred ninety-one thousand, eight hundred eighty-nine".