81697105 has 16 divisors (see below), whose sum is σ = 113304960. Its totient is φ = 55389312.

The previous prime is 81697103. The next prime is 81697129. The reversal of 81697105 is 50179618.

It is a cyclic number.

It is not a de Polignac number, because 81697105 - 2¹ = 81697103 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81697103) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9999 + ... + 16228.

It is an arithmetic number, because the mean of its divisors is an integer number (7081560).

Almost surely, 2^81697105 is an apocalyptic number.

It is an amenable number.

81697105 is a deficient number, since it is larger than the sum of its proper divisors (31607855).

81697105 is a wasteful number, since it uses less digits than its factorization.

81697105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26328.

The product of its (nonzero) digits is 15120, while the sum is 37.

The square root of 81697105 is about 9038.6450865160. The cubic root of 81697105 is about 433.9125610478.

The spelling of 81697105 in words is "eighty-one million, six hundred ninety-seven thousand, one hundred five".