71981961 has 8 divisors (see below), whose sum is σ = 101621664. Its totient is φ = 45165120.

The previous prime is 71981953. The next prime is 71981963. The reversal of 71981961 is 16918917.

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

It is not a de Polignac number, because 71981961 - 2³ = 71981953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71981963) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 705655 + ... + 705756.

It is an arithmetic number, because the mean of its divisors is an integer number (12702708).

Almost surely, 2^71981961 is an apocalyptic number.

It is an amenable number.

71981961 is a deficient number, since it is larger than the sum of its proper divisors (29639703).

71981961 is a wasteful number, since it uses less digits than its factorization.

71981961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1411431.

The product of its digits is 27216, while the sum is 42.

The square root of 71981961 is about 8484.2183493826. The cubic root of 71981961 is about 415.9820185306.

The spelling of 71981961 in words is "seventy-one million, nine hundred eighty-one thousand, nine hundred sixty-one".