81142201 has 8 divisors (see below), whose sum is σ = 94004864. Its totient is φ = 68597280.

The previous prime is 81142199. The next prime is 81142213. The reversal of 81142201 is 10224118.

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 81142201 - 2¹ = 81142199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81142291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78885 + ... + 79906.

It is an arithmetic number, because the mean of its divisors is an integer number (11750608).

Almost surely, 2^81142201 is an apocalyptic number.

It is an amenable number.

81142201 is a deficient number, since it is larger than the sum of its proper divisors (12862663).

81142201 is a wasteful number, since it uses less digits than its factorization.

81142201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158871.

The product of its (nonzero) digits is 128, while the sum is 19.

The square root of 81142201 is about 9007.8965913247. The cubic root of 81142201 is about 432.9279197737.

Adding to 81142201 its reverse (10224118), we get a palindrome (91366319).

The spelling of 81142201 in words is "eighty-one million, one hundred forty-two thousand, two hundred one".