81273654 has 72 divisors (see below), whose sum is σ = 223491528. Its totient is φ = 21107520.

The previous prime is 81273653. The next prime is 81273691. The reversal of 81273654 is 45637218.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81273653) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 5514 + ... + 13890.

It is an arithmetic number, because the mean of its divisors is an integer number (3104049).

Almost surely, 2^81273654 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81273654, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111745764).

81273654 is an abundant number, since it is smaller than the sum of its proper divisors (142217874).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81273654 is a wasteful number, since it uses less digits than its factorization.

81273654 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8410 (or 8400 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 81273654 is about 9015.1901810223. The cubic root of 81273654 is about 433.1615794022.

It can be divided in two parts, 8127 and 3654, that added together give a triangular number (11781 = T₁₅₃).

The spelling of 81273654 in words is "eighty-one million, two hundred seventy-three thousand, six hundred fifty-four".