81554 has 12 divisors (see below), whose sum is σ = 134862. Its totient is φ = 36960.

The previous prime is 81553. The next prime is 81559. The reversal of 81554 is 45518.

It can be written as a sum of positive squares in only one way, i.e., 75625 + 5929 = 275^2 + 77^2 .

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81551) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 74 + ... + 410.

2⁸¹⁵⁵⁴ is an apocalyptic number.

81554 is a deficient number, since it is larger than the sum of its proper divisors (53308).

81554 is a wasteful number, since it uses less digits than its factorization.

81554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361 (or 350 counting only the distinct ones).

The product of its digits is 800, while the sum is 23.

The square root of 81554 is about 285.5766096864. The cubic root of 81554 is about 43.3659058190.

The spelling of 81554 in words is "eighty-one thousand, five hundred fifty-four".