81180907 has 4 divisors (see below), whose sum is σ = 81198936. Its totient is φ = 81162880.

The previous prime is 81180893. The next prime is 81180917. The reversal of 81180907 is 70908118.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81180907 is a prime.

It is a super-2 number, since 2×81180907² = 13180679322685298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81180917) 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, 4107 + ... + 13387.

It is an arithmetic number, because the mean of its divisors is an integer number (20299734).

Almost surely, 2^81180907 is an apocalyptic number.

81180907 is a deficient number, since it is larger than the sum of its proper divisors (18029).

81180907 is an equidigital number, since it uses as much as digits as its factorization.

81180907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18028.

The product of its (nonzero) digits is 4032, while the sum is 34.

The square root of 81180907 is about 9010.0447834625. The cubic root of 81180907 is about 432.9967464513.

It can be divided in two parts, 811 and 80907, that added together give a palindrome (81718).

The spelling of 81180907 in words is "eighty-one million, one hundred eighty thousand, nine hundred seven".