81894265 has 4 divisors (see below), whose sum is σ = 98273124. Its totient is φ = 65515408.

The previous prime is 81894251. The next prime is 81894277. The reversal of 81894265 is 56249818.

It is a happy number.

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 12538681 + 69355584 = 3541^2 + 8328^2 .

It is a cyclic number.

It is not a de Polignac number, because 81894265 - 2⁵ = 81894233 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8189422 + ... + 8189431.

It is an arithmetic number, because the mean of its divisors is an integer number (24568281).

Almost surely, 2^81894265 is an apocalyptic number.

It is an amenable number.

81894265 is a deficient number, since it is larger than the sum of its proper divisors (16378859).

81894265 is a wasteful number, since it uses less digits than its factorization.

81894265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16378858.

The product of its digits is 138240, while the sum is 43.

The square root of 81894265 is about 9049.5450161873. The cubic root of 81894265 is about 434.2613350265.

The spelling of 81894265 in words is "eighty-one million, eight hundred ninety-four thousand, two hundred sixty-five".