81773837 has 4 divisors (see below), whose sum is σ = 81884640. Its totient is φ = 81663036.

The previous prime is 81773833. The next prime is 81773849. The reversal of 81773837 is 73837718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81773837 - 2² = 81773833 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81773833) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54287 + ... + 55772.

It is an arithmetic number, because the mean of its divisors is an integer number (20471160).

Almost surely, 2^81773837 is an apocalyptic number.

It is an amenable number.

81773837 is a deficient number, since it is larger than the sum of its proper divisors (110803).

81773837 is a wasteful number, since it uses less digits than its factorization.

81773837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110802.

The product of its digits is 197568, while the sum is 44.

The square root of 81773837 is about 9042.8887530479. Note that the first 3 decimals coincide. The cubic root of 81773837 is about 434.0483657793.

The spelling of 81773837 in words is "eighty-one million, seven hundred seventy-three thousand, eight hundred thirty-seven".