81762889 has 4 divisors (see below), whose sum is σ = 88052356. Its totient is φ = 75473424.

The previous prime is 81762887. The next prime is 81762893. The reversal of 81762889 is 98826718.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 98826718 = 2 ⋅49413359.

It can be written as a sum of positive squares in 2 ways, for example, as 4182025 + 77580864 = 2045^2 + 8808^2 .

It is not a de Polignac number, because 81762889 - 2¹ = 81762887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81762881) 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, 3144714 + ... + 3144739.

It is an arithmetic number, because the mean of its divisors is an integer number (22013089).

Almost surely, 2^81762889 is an apocalyptic number.

It is an amenable number.

81762889 is a deficient number, since it is larger than the sum of its proper divisors (6289467).

81762889 is a wasteful number, since it uses less digits than its factorization.

81762889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6289466.

The product of its digits is 387072, while the sum is 49.

The square root of 81762889 is about 9042.2833952492. The cubic root of 81762889 is about 434.0289945730.

The spelling of 81762889 in words is "eighty-one million, seven hundred sixty-two thousand, eight hundred eighty-nine".