81988255 has 4 divisors (see below), whose sum is σ = 98385912. Its totient is φ = 65590600.

The previous prime is 81988243. The next prime is 81988303. The reversal of 81988255 is 55288918.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 81988255 - 2⁵ = 81988223 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8198821 + ... + 8198830.

It is an arithmetic number, because the mean of its divisors is an integer number (24596478).

Almost surely, 2^81988255 is an apocalyptic number.

81988255 is a deficient number, since it is larger than the sum of its proper divisors (16397657).

81988255 is a wasteful number, since it uses less digits than its factorization.

81988255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16397656.

The product of its digits is 230400, while the sum is 46.

The square root of 81988255 is about 9054.7366057771. The cubic root of 81988255 is about 434.4274053364.

The spelling of 81988255 in words is "eighty-one million, nine hundred eighty-eight thousand, two hundred fifty-five".