71981541 has 10 divisors (see below), whose sum is σ = 107528102. Its totient is φ = 47987640.

The previous prime is 71981537. The next prime is 71981543. The reversal of 71981541 is 14518917.

It can be written as a sum of positive squares in only one way, i.e., 68409441 + 3572100 = 8271^2 + 1890^2 .

It is not a de Polignac number, because 71981541 - 2² = 71981537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 71981496 and 71981505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71981543) 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 9 ways as a sum of consecutive naturals, for example, 444250 + ... + 444411.

Almost surely, 2^71981541 is an apocalyptic number.

It is an amenable number.

71981541 is a deficient number, since it is larger than the sum of its proper divisors (35546561).

71981541 is an equidigital number, since it uses as much as digits as its factorization.

71981541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888673 (or 888664 counting only the distinct ones).

The product of its digits is 10080, while the sum is 36.

The square root of 71981541 is about 8484.1935975083. The cubic root of 71981541 is about 415.9812094724.

The spelling of 71981541 in words is "seventy-one million, nine hundred eighty-one thousand, five hundred forty-one".