81025911 has 6 divisors (see below), whose sum is σ = 117037440. Its totient is φ = 54017268.

The previous prime is 81025891. The next prime is 81025949. The reversal of 81025911 is 11952018.

It is not a de Polignac number, because 81025911 - 2⁷ = 81025783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81025811) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4501431 + ... + 4501448.

It is an arithmetic number, because the mean of its divisors is an integer number (19506240).

Almost surely, 2^81025911 is an apocalyptic number.

81025911 is a deficient number, since it is larger than the sum of its proper divisors (36011529).

81025911 is a wasteful number, since it uses less digits than its factorization.

81025911 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9002885 (or 9002882 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 27.

The square root of 81025911 is about 9001.4393848984. The cubic root of 81025911 is about 432.7210021349.

Adding to 81025911 its reverse (11952018), we get a palindrome (92977929).

The spelling of 81025911 in words is "eighty-one million, twenty-five thousand, nine hundred eleven".