71817481 has 4 divisors (see below), whose sum is σ = 73758532. Its totient is φ = 69876432.

The previous prime is 71817467. The next prime is 71817509. The reversal of 71817481 is 18471817.

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 34105600 + 37711881 = 5840^2 + 6141^2 .

It is a cyclic number.

It is not a de Polignac number, because 71817481 - 2¹⁹ = 71293193 is a prime.

It is a super-2 number, since 2×71817481² = 10315501154370722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37), and also a Moran number because the ratio is a prime number: 1941013 = 71817481 / (7 + 1 + 8 + 1 + 7 + 4 + 8 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 71817481.

It is not an unprimeable number, because it can be changed into a prime (71815481) 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, 970470 + ... + 970543.

It is an arithmetic number, because the mean of its divisors is an integer number (18439633).

Almost surely, 2^71817481 is an apocalyptic number.

It is an amenable number.

71817481 is a deficient number, since it is larger than the sum of its proper divisors (1941051).

71817481 is a wasteful number, since it uses less digits than its factorization.

71817481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1941050.

The product of its digits is 12544, while the sum is 37.

The square root of 71817481 is about 8474.5195144032. The cubic root of 71817481 is about 415.6649349081.

The spelling of 71817481 in words is "seventy-one million, eight hundred seventeen thousand, four hundred eighty-one".