81551854 has 8 divisors (see below), whose sum is σ = 123035400. Its totient is φ = 40540056.

The previous prime is 81551831. The next prime is 81551867. The reversal of 81551854 is 45815518.

It is a sphenic number, since it is the product of 3 distinct primes.

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, 117504 + ... + 118195.

It is an arithmetic number, because the mean of its divisors is an integer number (15379425).

Almost surely, 2^81551854 is an apocalyptic number.

81551854 is a deficient number, since it is larger than the sum of its proper divisors (41483546).

81551854 is a wasteful number, since it uses less digits than its factorization.

81551854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235874.

The product of its digits is 32000, while the sum is 37.

The square root of 81551854 is about 9030.6065134076. The cubic root of 81551854 is about 433.6552544099.

The spelling of 81551854 in words is "eighty-one million, five hundred fifty-one thousand, eight hundred fifty-four".