81143501 has 8 divisors (see below), whose sum is σ = 82149984. Its totient is φ = 80141200.

The previous prime is 81143459. The next prime is 81143611. The reversal of 81143501 is 10534118.

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 81143501 - 2⁶ = 81143437 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 (81143201) 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, 56150 + ... + 57576.

It is an arithmetic number, because the mean of its divisors is an integer number (10268748).

Almost surely, 2^81143501 is an apocalyptic number.

It is an amenable number.

81143501 is a deficient number, since it is larger than the sum of its proper divisors (1006483).

81143501 is a wasteful number, since it uses less digits than its factorization.

81143501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2091.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 81143501 is about 9007.9687499458. The cubic root of 81143501 is about 432.9302317777.

Adding to 81143501 its reverse (10534118), we get a palindrome (91677619).

The spelling of 81143501 in words is "eighty-one million, one hundred forty-three thousand, five hundred one".