67131881 has 4 divisors (see below), whose sum is σ = 67204164. Its totient is φ = 67059600.

The previous prime is 67131877. The next prime is 67131893. The reversal of 67131881 is 18813176.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24098281 + 43033600 = 4909^2 + 6560^2 .

It is a cyclic number.

It is not a de Polignac number, because 67131881 - 2² = 67131877 is a prime.

It is a super-2 number, since 2×67131881² = 9013378893196322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (67131851) 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, 34730 + ... + 36611.

It is an arithmetic number, because the mean of its divisors is an integer number (16801041).

Almost surely, 2^67131881 is an apocalyptic number.

It is an amenable number.

67131881 is a deficient number, since it is larger than the sum of its proper divisors (72283).

67131881 is an equidigital number, since it uses as much as digits as its factorization.

67131881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72282.

The product of its digits is 8064, while the sum is 35.

The square root of 67131881 is about 8193.4047257535. The cubic root of 67131881 is about 406.4211234584.

The spelling of 67131881 in words is "sixty-seven million, one hundred thirty-one thousand, eight hundred eighty-one".