81155361 has 8 divisors (see below), whose sum is σ = 123665344. Its totient is φ = 46374480.

The previous prime is 81155353. The next prime is 81155377. The reversal of 81155361 is 16355118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81155361 - 2³ = 81155353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81151361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1932250 + ... + 1932291.

It is an arithmetic number, because the mean of its divisors is an integer number (15458168).

Almost surely, 2^81155361 is an apocalyptic number.

It is an amenable number.

81155361 is a deficient number, since it is larger than the sum of its proper divisors (42509983).

81155361 is a wasteful number, since it uses less digits than its factorization.

81155361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3864551.

The product of its digits is 3600, while the sum is 30.

The square root of 81155361 is about 9008.6270319067. The cubic root of 81155361 is about 432.9513232283.

The spelling of 81155361 in words is "eighty-one million, one hundred fifty-five thousand, three hundred sixty-one".