81859151 has 8 divisors (see below), whose sum is σ = 89697024. Its totient is φ = 74087320.

The previous prime is 81859123. The next prime is 81859153. The reversal of 81859151 is 15195818.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81859151 - 2¹⁴ = 81842767 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81859153) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13895 + ... + 18888.

It is an arithmetic number, because the mean of its divisors is an integer number (11212128).

Almost surely, 2^81859151 is an apocalyptic number.

81859151 is a deficient number, since it is larger than the sum of its proper divisors (7837873).

81859151 is a wasteful number, since it uses less digits than its factorization.

81859151 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33021.

The product of its digits is 14400, while the sum is 38.

The square root of 81859151 is about 9047.6047106403. The cubic root of 81859151 is about 434.1992597296.

The spelling of 81859151 in words is "eighty-one million, eight hundred fifty-nine thousand, one hundred fifty-one".