813040081 has 4 divisors (see below), whose sum is σ = 929188672. Its totient is φ = 696891492.

The previous prime is 813040049. The next prime is 813040091. The reversal of 813040081 is 180040318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 180040318 = 2 ⋅90020159.

It is a cyclic number.

It is not a de Polignac number, because 813040081 - 2⁵ = 813040049 is a prime.

It is a super-2 number, since 2×813040081² = 1322068346624973122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (813040031) 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, 58074285 + ... + 58074298.

It is an arithmetic number, because the mean of its divisors is an integer number (232297168).

Almost surely, 2^813040081 is an apocalyptic number.

It is an amenable number.

813040081 is a deficient number, since it is larger than the sum of its proper divisors (116148591).

813040081 is a wasteful number, since it uses less digits than its factorization.

813040081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116148590.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 813040081 is about 28513.8577011249. The cubic root of 813040081 is about 933.3344981136.

Adding to 813040081 its reverse (180040318), we get a palindrome (993080399).

The spelling of 813040081 in words is "eight hundred thirteen million, forty thousand, eighty-one".