81537255 has 12 divisors (see below), whose sum is σ = 141331320. Its totient is φ = 43486512.

The previous prime is 81537229. The next prime is 81537257. The reversal of 81537255 is 55273518.

It is not a de Polignac number, because 81537255 - 2²⁴ = 64760039 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81537257) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 905925 + ... + 906014.

It is an arithmetic number, because the mean of its divisors is an integer number (11777610).

Almost surely, 2^81537255 is an apocalyptic number.

81537255 is a deficient number, since it is larger than the sum of its proper divisors (59794065).

81537255 is a wasteful number, since it uses less digits than its factorization.

81537255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1811950 (or 1811947 counting only the distinct ones).

The product of its digits is 42000, while the sum is 36.

The square root of 81537255 is about 9029.7981705019. The cubic root of 81537255 is about 433.6293759430.

The spelling of 81537255 in words is "eighty-one million, five hundred thirty-seven thousand, two hundred fifty-five".