81499837 has 12 divisors (see below), whose sum is σ = 85316736. Its totient is φ = 77769720.

The previous prime is 81499811. The next prime is 81499861. The reversal of 81499837 is 73899418.

It is a happy number.

It is not a de Polignac number, because 81499837 - 2¹¹ = 81497789 is a prime.

It is a Duffinian number.

Its product of digits (435456) is a multiple of the sum of its prime factors (448).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81499877) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 499918 + ... + 500080.

It is an arithmetic number, because the mean of its divisors is an integer number (7109728).

Almost surely, 2^81499837 is an apocalyptic number.

It is an amenable number.

81499837 is a deficient number, since it is larger than the sum of its proper divisors (3816899).

81499837 is a wasteful number, since it uses less digits than its factorization.

81499837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448 (or 321 counting only the distinct ones).

The product of its digits is 435456, while the sum is 49.

The square root of 81499837 is about 9027.7260148943. The cubic root of 81499837 is about 433.5630339719.

The spelling of 81499837 in words is "eighty-one million, four hundred ninety-nine thousand, eight hundred thirty-seven".