81984825 has 48 divisors (see below), whose sum is σ = 162211840. Its totient is φ = 40357440.

The previous prime is 81984781. The next prime is 81984839. The reversal of 81984825 is 52848918.

It is a happy number.

81984825 is a `hidden beast` number, since 81 + 98 + 482 + 5 = 666.

It is not a de Polignac number, because 81984825 - 2⁷ = 81984697 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 4104 + ... + 13446.

Almost surely, 2^81984825 is an apocalyptic number.

It is an amenable number.

81984825 is a deficient number, since it is larger than the sum of its proper divisors (80227015).

81984825 is a wasteful number, since it uses less digits than its factorization.

81984825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9375 (or 9364 counting only the distinct ones).

The product of its digits is 184320, while the sum is 45.

The square root of 81984825 is about 9054.5472001641. The cubic root of 81984825 is about 434.4213471241.

It can be divided in two parts, 81 and 984825, that added together give a triangular number (984906 = T₁₄₀₃).

The spelling of 81984825 in words is "eighty-one million, nine hundred eighty-four thousand, eight hundred twenty-five".