81437 has 8 divisors (see below), whose sum is σ = 87552. Its totient is φ = 75600.

The previous prime is 81421. The next prime is 81439. The reversal of 81437 is 73418.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81437 - 2⁴ = 81421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 81437.

It is not an unprimeable number, because it can be changed into a prime (81439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1112 + ... + 1182.

It is an arithmetic number, because the mean of its divisors is an integer number (10944).

2⁸¹⁴³⁷ is an apocalyptic number.

It is an amenable number.

81437 is a deficient number, since it is larger than the sum of its proper divisors (6115).

81437 is a wasteful number, since it uses less digits than its factorization.

81437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139.

The product of its digits is 672, while the sum is 23.

The square root of 81437 is about 285.3716874534. The cubic root of 81437 is about 43.3451578513.

The spelling of 81437 in words is "eighty-one thousand, four hundred thirty-seven".