81309001 has 16 divisors (see below), whose sum is σ = 86614528. Its totient is φ = 76204800.

The previous prime is 81308971. The next prime is 81309029. The reversal of 81309001 is 10090318.

It is a cyclic number.

It is not a de Polignac number, because 81309001 - 2⁷ = 81308873 is a prime.

It is a super-2 number, since 2×81309001² = 13222307287236002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81309031) 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 15 ways as a sum of consecutive naturals, for example, 241105 + ... + 241441.

It is an arithmetic number, because the mean of its divisors is an integer number (5413408).

Almost surely, 2^81309001 is an apocalyptic number.

It is an amenable number.

81309001 is a deficient number, since it is larger than the sum of its proper divisors (5305527).

81309001 is a wasteful number, since it uses less digits than its factorization.

81309001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592.

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 81309001 is about 9017.1503813566. The cubic root of 81309001 is about 433.2243662238.

Adding to 81309001 its reverse (10090318), we get a palindrome (91399319).

The spelling of 81309001 in words is "eighty-one million, three hundred nine thousand, one".