71981642 has 8 divisors (see below), whose sum is σ = 108279396. Its totient is φ = 35888512.

The previous prime is 71981617. The next prime is 71981677. The reversal of 71981642 is 24618917.

It can be written as a sum of positive squares in 2 ways, for example, as 65626201 + 6355441 = 8101^2 + 2521^2 .

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

It is a junction number, because it is equal to n+sod(n) for n = 71981596 and 71981605.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 50273 + ... + 51684.

Almost surely, 2^71981642 is an apocalyptic number.

71981642 is a deficient number, since it is larger than the sum of its proper divisors (36297754).

71981642 is a wasteful number, since it uses less digits than its factorization.

71981642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102312.

The product of its digits is 24192, while the sum is 38.

The square root of 71981642 is about 8484.1995497513. The cubic root of 71981642 is about 415.9814040319.

The spelling of 71981642 in words is "seventy-one million, nine hundred eighty-one thousand, six hundred forty-two".