81037137 has 4 divisors (see below), whose sum is σ = 108049520. Its totient is φ = 54024756.

The previous prime is 81037091. The next prime is 81037153. The reversal of 81037137 is 73173018.

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 not a de Polignac number, because 81037137 - 2¹² = 81033041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81032137) 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, 13506187 + ... + 13506192.

It is an arithmetic number, because the mean of its divisors is an integer number (27012380).

Almost surely, 2^81037137 is an apocalyptic number.

It is an amenable number.

81037137 is a deficient number, since it is larger than the sum of its proper divisors (27012383).

81037137 is a wasteful number, since it uses less digits than its factorization.

81037137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27012382.

The product of its (nonzero) digits is 3528, while the sum is 30.

The square root of 81037137 is about 9002.0629302399. The cubic root of 81037137 is about 432.7409854611.

The spelling of 81037137 in words is "eighty-one million, thirty-seven thousand, one hundred thirty-seven".