81555455 has 8 divisors (see below), whose sum is σ = 98070432. Its totient is φ = 65108448.

The previous prime is 81555449. The next prime is 81555457. The reversal of 81555455 is 55455518.

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

It is a cyclic number.

It is not a de Polignac number, because 81555455 - 2²⁶ = 14446591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81555457) 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, 14312 + ... + 19181.

It is an arithmetic number, because the mean of its divisors is an integer number (12258804).

Almost surely, 2^81555455 is an apocalyptic number.

81555455 is a deficient number, since it is larger than the sum of its proper divisors (16514977).

81555455 is a wasteful number, since it uses less digits than its factorization.

81555455 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33985.

The product of its digits is 100000, while the sum is 38.

The square root of 81555455 is about 9030.8058887344. The cubic root of 81555455 is about 433.6616371366.

The spelling of 81555455 in words is "eighty-one million, five hundred fifty-five thousand, four hundred fifty-five".