81696567 has 16 divisors (see below), whose sum is σ = 113379840. Its totient is φ = 52262112.

The previous prime is 81696547. The next prime is 81696607. The reversal of 81696567 is 76569618.

It is not a de Polignac number, because 81696567 - 2¹⁶ = 81631031 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81696547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11718 + ... + 17340.

It is an arithmetic number, because the mean of its divisors is an integer number (7086240).

Almost surely, 2^81696567 is an apocalyptic number.

81696567 is a gapful number since it is divisible by the number (87) formed by its first and last digit.

81696567 is a deficient number, since it is larger than the sum of its proper divisors (31683273).

81696567 is a wasteful number, since it uses less digits than its factorization.

81696567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5822.

The product of its digits is 544320, while the sum is 48.

The square root of 81696567 is about 9038.6153253693. The cubic root of 81696567 is about 433.9116085641.

The spelling of 81696567 in words is "eighty-one million, six hundred ninety-six thousand, five hundred sixty-seven".