81270137 has 8 divisors (see below), whose sum is σ = 87805704. Its totient is φ = 74775168.

The previous prime is 81270121. The next prime is 81270139. The reversal of 81270137 is 73107218.

It can be written as a sum of positive squares in 4 ways, for example, as 3759721 + 77510416 = 1939^2 + 8804^2 .

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

It is not a de Polignac number, because 81270137 - 2⁴ = 81270121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81270139) 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 7 ways as a sum of consecutive naturals, for example, 5918 + ... + 14055.

It is an arithmetic number, because the mean of its divisors is an integer number (10975713).

Almost surely, 2^81270137 is an apocalyptic number.

It is an amenable number.

81270137 is a deficient number, since it is larger than the sum of its proper divisors (6535567).

81270137 is a wasteful number, since it uses less digits than its factorization.

81270137 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20299.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 81270137 is about 9014.9951192444. The cubic root of 81270137 is about 433.1553311648.

The spelling of 81270137 in words is "eighty-one million, two hundred seventy thousand, one hundred thirty-seven".