81807107 has 4 divisors (see below), whose sum is σ = 82842720. Its totient is φ = 80771496.

The previous prime is 81807091. The next prime is 81807127. The reversal of 81807107 is 70170818.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81807107 - 2⁴ = 81807091 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81807127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 517688 + ... + 517845.

It is an arithmetic number, because the mean of its divisors is an integer number (20710680).

Almost surely, 2^81807107 is an apocalyptic number.

81807107 is a deficient number, since it is larger than the sum of its proper divisors (1035613).

81807107 is a wasteful number, since it uses less digits than its factorization.

81807107 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1035612.

The product of its (nonzero) digits is 3136, while the sum is 32.

The square root of 81807107 is about 9044.7281330065. The cubic root of 81807107 is about 434.1072225468.

The spelling of 81807107 in words is "eighty-one million, eight hundred seven thousand, one hundred seven".