81673625 has 16 divisors (see below), whose sum is σ = 111196800. Its totient is φ = 59398000.

The previous prime is 81673589. The next prime is 81673637. The reversal of 81673625 is 52637618.

It is not a de Polignac number, because 81673625 - 2⁸ = 81673369 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28325 + ... + 31074.

It is an arithmetic number, because the mean of its divisors is an integer number (6949800).

Almost surely, 2^81673625 is an apocalyptic number.

It is an amenable number.

81673625 is a deficient number, since it is larger than the sum of its proper divisors (29523175).

81673625 is a wasteful number, since it uses less digits than its factorization.

81673625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59425 (or 59415 counting only the distinct ones).

The product of its digits is 60480, while the sum is 38.

The square root of 81673625 is about 9037.3461259376. The cubic root of 81673625 is about 433.8709877952.

The spelling of 81673625 in words is "eighty-one million, six hundred seventy-three thousand, six hundred twenty-five".