81000143 has 16 divisors (see below), whose sum is σ = 94334016. Its totient is φ = 68117760.

The previous prime is 81000113. The next prime is 81000149. The reversal of 81000143 is 34100018.

It is a happy number.

It is not a de Polignac number, because 81000143 - 2¹⁸ = 80737999 is a prime.

It is a super-2 number, since 2×81000143² = 13122046332040898, which contains 22 as substring.

81000143 is a modest number, since divided by 143 gives 81 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81000149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 149453 + ... + 149993.

It is an arithmetic number, because the mean of its divisors is an integer number (5895876).

Almost surely, 2^81000143 is an apocalyptic number.

81000143 is a deficient number, since it is larger than the sum of its proper divisors (13333873).

81000143 is a wasteful number, since it uses less digits than its factorization.

81000143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 914.

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 81000143 is about 9000.0079444409. The cubic root of 81000143 is about 432.6751257114.

The spelling of 81000143 in words is "eighty-one million, one hundred forty-three", and thus it is an aban number.