81511254 has 96 divisors (see below), whose sum is σ = 207567360. Its totient is φ = 22852800.

The previous prime is 81511249. The next prime is 81511271. The reversal of 81511254 is 45211518.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 176584 + ... + 177044.

It is an arithmetic number, because the mean of its divisors is an integer number (2162160).

Almost surely, 2^81511254 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81511254, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103783680).

81511254 is an abundant number, since it is smaller than the sum of its proper divisors (126056106).

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

81511254 is a wasteful number, since it uses less digits than its factorization.

81511254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546 (or 543 counting only the distinct ones).

The product of its digits is 1600, while the sum is 27.

The square root of 81511254 is about 9028.3583225302. The cubic root of 81511254 is about 433.5832784216.

The spelling of 81511254 in words is "eighty-one million, five hundred eleven thousand, two hundred fifty-four".