81844837 has 12 divisors (see below), whose sum is σ = 86904576. Its totient is φ = 77066280.

The previous prime is 81844801. The next prime is 81844843. The reversal of 81844837 is 73844818.

It is not a de Polignac number, because 81844837 - 2⁷ = 81844709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81844793 and 81844802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81844877) 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 11 ways as a sum of consecutive naturals, for example, 68358 + ... + 69544.

It is an arithmetic number, because the mean of its divisors is an integer number (7242048).

Almost surely, 2^81844837 is an apocalyptic number.

It is an amenable number.

81844837 is a deficient number, since it is larger than the sum of its proper divisors (5059739).

81844837 is a wasteful number, since it uses less digits than its factorization.

81844837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416 (or 1397 counting only the distinct ones).

The product of its digits is 172032, while the sum is 43.

The square root of 81844837 is about 9046.8136379612. The cubic root of 81844837 is about 434.1739500344.

The spelling of 81844837 in words is "eighty-one million, eight hundred forty-four thousand, eight hundred thirty-seven".