71542381 has 4 divisors (see below), whose sum is σ = 71675164. Its totient is φ = 71409600.

The previous prime is 71542379. The next prime is 71542453. The reversal of 71542381 is 18324517.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 18324517 = 199 ⋅92083.

It can be written as a sum of positive squares in 2 ways, for example, as 34222500 + 37319881 = 5850^2 + 6109^2 .

It is a cyclic number.

It is not a de Polignac number, because 71542381 - 2¹ = 71542379 is a prime.

It is a super-2 number, since 2×71542381² = 10236624558298322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71542301) 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 3 ways as a sum of consecutive naturals, for example, 65580 + ... + 66661.

It is an arithmetic number, because the mean of its divisors is an integer number (17918791).

Almost surely, 2^71542381 is an apocalyptic number.

It is an amenable number.

71542381 is a deficient number, since it is larger than the sum of its proper divisors (132783).

71542381 is a wasteful number, since it uses less digits than its factorization.

71542381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 132782.

The product of its digits is 6720, while the sum is 31.

The square root of 71542381 is about 8458.2729324609. The cubic root of 71542381 is about 415.1335148865.

Adding to 71542381 its reverse (18324517), we get a palindrome (89866898).

The spelling of 71542381 in words is "seventy-one million, five hundred forty-two thousand, three hundred eighty-one".