81654081 has 4 divisors (see below), whose sum is σ = 108872112. Its totient is φ = 54436052.

The previous prime is 81654073. The next prime is 81654107. The reversal of 81654081 is 18045618.

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.

It is a cyclic number.

It is not a de Polignac number, because 81654081 - 2³ = 81654073 is a prime.

It is a super-2 number, since 2×81654081² = 13334777887909122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81654011) 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, 13609011 + ... + 13609016.

It is an arithmetic number, because the mean of its divisors is an integer number (27218028).

Almost surely, 2^81654081 is an apocalyptic number.

It is an amenable number.

81654081 is a deficient number, since it is larger than the sum of its proper divisors (27218031).

81654081 is a wasteful number, since it uses less digits than its factorization.

81654081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27218030.

The product of its (nonzero) digits is 7680, while the sum is 33.

The square root of 81654081 is about 9036.2647703573. The cubic root of 81654081 is about 433.8363774746.

Adding to 81654081 its reverse (18045618), we get a palindrome (99699699).

It can be divided in two parts, 8165 and 4081, that added together give a triangular number (12246 = T₁₅₆).

The spelling of 81654081 in words is "eighty-one million, six hundred fifty-four thousand, eighty-one".