81676507 has 8 divisors (see below), whose sum is σ = 89229312. Its totient is φ = 74145000.

The previous prime is 81676477. The next prime is 81676531. The reversal of 81676507 is 70567618.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81676507 - 2⁷ = 81676379 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81676507.

It is not an unprimeable number, because it can be changed into a prime (81676597) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3318 + ... + 13204.

It is an arithmetic number, because the mean of its divisors is an integer number (11153664).

Almost surely, 2^81676507 is an apocalyptic number.

81676507 is a deficient number, since it is larger than the sum of its proper divisors (7552805).

81676507 is a wasteful number, since it uses less digits than its factorization.

81676507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10649.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 81676507 is about 9037.5055739955. The cubic root of 81676507 is about 433.8760910399.

Subtracting from 81676507 its reverse (70567618), we obtain a square (11108889 = 3333²).

The spelling of 81676507 in words is "eighty-one million, six hundred seventy-six thousand, five hundred seven".