71818091 has 4 divisors (see below), whose sum is σ = 71878512. Its totient is φ = 71757672.

The previous prime is 71818051. The next prime is 71818093. The reversal of 71818091 is 19081817.

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

It is a cyclic number.

It is not a de Polignac number, because 71818091 - 2⁶ = 71818027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71818093) 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, 28391 + ... + 30816.

It is an arithmetic number, because the mean of its divisors is an integer number (17969628).

Almost surely, 2^71818091 is an apocalyptic number.

71818091 is a deficient number, since it is larger than the sum of its proper divisors (60421).

71818091 is a wasteful number, since it uses less digits than its factorization.

71818091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60420.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 71818091 is about 8474.5555045678. Note that the first 4 decimals coincide. The cubic root of 71818091 is about 415.6661117567. Note that the first 3 decimals are identical.

The spelling of 71818091 in words is "seventy-one million, eight hundred eighteen thousand, ninety-one".