71681947 has 4 divisors (see below), whose sum is σ = 71701416. Its totient is φ = 71662480.

The previous prime is 71681941. The next prime is 71681957. The reversal of 71681947 is 74918617.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71681947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71681941) 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, 2338 + ... + 12199.

It is an arithmetic number, because the mean of its divisors is an integer number (17925354).

Almost surely, 2^71681947 is an apocalyptic number.

71681947 is a deficient number, since it is larger than the sum of its proper divisors (19469).

71681947 is a wasteful number, since it uses less digits than its factorization.

71681947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19468.

The product of its digits is 84672, while the sum is 43.

The square root of 71681947 is about 8466.5191785054. The cubic root of 71681947 is about 415.4032891951.

The spelling of 71681947 in words is "seventy-one million, six hundred eighty-one thousand, nine hundred forty-seven".