81349801 has 4 divisors (see below), whose sum is σ = 87607492. Its totient is φ = 75092112.

The previous prime is 81349789. The next prime is 81349823. The reversal of 81349801 is 10894318.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6007401 + 75342400 = 2451^2 + 8680^2 .

It is a cyclic number.

It is not a de Polignac number, because 81349801 - 2⁵ = 81349769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81349841) 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 3 ways as a sum of consecutive naturals, for example, 3128826 + ... + 3128851.

It is an arithmetic number, because the mean of its divisors is an integer number (21901873).

Almost surely, 2^81349801 is an apocalyptic number.

It is an amenable number.

81349801 is a deficient number, since it is larger than the sum of its proper divisors (6257691).

81349801 is a wasteful number, since it uses less digits than its factorization.

81349801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6257690.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 81349801 is about 9019.4124531479. The cubic root of 81349801 is about 433.2968165810.

The spelling of 81349801 in words is "eighty-one million, three hundred forty-nine thousand, eight hundred one".