81863025 has 36 divisors (see below), whose sum is σ = 137977776. Its totient is φ = 42824000.

The previous prime is 81863017. The next prime is 81863051. The reversal of 81863025 is 52036818.

It is a happy number.

It is not a de Polignac number, because 81863025 - 2³ = 81863017 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 765022 + ... + 765128.

It is an arithmetic number, because the mean of its divisors is an integer number (3832716).

Almost surely, 2^81863025 is an apocalyptic number.

It is an amenable number.

81863025 is a deficient number, since it is larger than the sum of its proper divisors (56114751).

81863025 is a wasteful number, since it uses less digits than its factorization.

81863025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 81863025 is about 9047.8187979203. The cubic root of 81863025 is about 434.2061091426.

It can be divided in two parts, 8186 and 3025, that added together give a palindrome (11211).

The spelling of 81863025 in words is "eighty-one million, eight hundred sixty-three thousand, twenty-five".