81140655 has 16 divisors (see below), whose sum is σ = 129952224. Its totient is φ = 43232640.

The previous prime is 81140651. The next prime is 81140669. The reversal of 81140655 is 55604118.

It is not a de Polignac number, because 81140655 - 2² = 81140651 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81140651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18757 + ... + 22673.

It is an arithmetic number, because the mean of its divisors is an integer number (8122014).

Almost surely, 2^81140655 is an apocalyptic number.

81140655 is a deficient number, since it is larger than the sum of its proper divisors (48811569).

81140655 is a wasteful number, since it uses less digits than its factorization.

81140655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5306.

The product of its (nonzero) digits is 4800, while the sum is 30.

The square root of 81140655 is about 9007.8107773199. The cubic root of 81140655 is about 432.9251702352.

The spelling of 81140655 in words is "eighty-one million, one hundred forty thousand, six hundred fifty-five".