81413091 has 12 divisors (see below), whose sum is σ = 117956280. Its totient is φ = 54109440.

The previous prime is 81413083. The next prime is 81413113. The reversal of 81413091 is 19031418.

It is not a de Polignac number, because 81413091 - 2³ = 81413083 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81413011) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10686 + ... + 16643.

It is an arithmetic number, because the mean of its divisors is an integer number (9829690).

Almost surely, 2^81413091 is an apocalyptic number.

81413091 is a deficient number, since it is larger than the sum of its proper divisors (36543189).

81413091 is a wasteful number, since it uses less digits than its factorization.

81413091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27666 (or 27663 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 81413091 is about 9022.9203143993. The cubic root of 81413091 is about 433.4091555028.

The spelling of 81413091 in words is "eighty-one million, four hundred thirteen thousand, ninety-one".