81852447 has 4 divisors (see below), whose sum is σ = 109136600. Its totient is φ = 54568296.

The previous prime is 81852443. The next prime is 81852451. The reversal of 81852447 is 74425818.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (81852443) and next prime (81852451).

It is not a de Polignac number, because 81852447 - 2² = 81852443 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 (81852443) 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, 13642072 + ... + 13642077.

It is an arithmetic number, because the mean of its divisors is an integer number (27284150).

Almost surely, 2^81852447 is an apocalyptic number.

81852447 is a deficient number, since it is larger than the sum of its proper divisors (27284153).

81852447 is a wasteful number, since it uses less digits than its factorization.

81852447 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27284152.

The product of its digits is 71680, while the sum is 39.

The square root of 81852447 is about 9047.2342182570. The cubic root of 81852447 is about 434.1874062339.

The spelling of 81852447 in words is "eighty-one million, eight hundred fifty-two thousand, four hundred forty-seven".