81707025 has 12 divisors (see below), whose sum is σ = 135089072. Its totient is φ = 43577040.

The previous prime is 81706997. The next prime is 81707027. The reversal of 81707025 is 52070718.

It is a happy number.

It is not a de Polignac number, because 81707025 - 2⁵ = 81706993 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81706983 and 81707001.

It is not an unprimeable number, because it can be changed into a prime (81707027) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 544639 + ... + 544788.

Almost surely, 2^81707025 is an apocalyptic number.

It is an amenable number.

81707025 is a deficient number, since it is larger than the sum of its proper divisors (53382047).

81707025 is a wasteful number, since it uses less digits than its factorization.

81707025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1089440 (or 1089435 counting only the distinct ones).

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 81707025 is about 9039.1938246726. The cubic root of 81707025 is about 433.9301228222.

The spelling of 81707025 in words is "eighty-one million, seven hundred seven thousand, twenty-five".