71978986 has 32 divisors (see below), whose sum is σ = 121519440. Its totient is φ = 31804416.

The previous prime is 71978981. The next prime is 71979001. The reversal of 71978986 is 68987917.

It can be written as a sum of positive squares in 8 ways, for example, as 52345225 + 19633761 = 7235^2 + 4431^2 .

It is not an unprimeable number, because it can be changed into a prime (71978981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35496 + ... + 37468.

Almost surely, 2^71978986 is an apocalyptic number.

71978986 is a deficient number, since it is larger than the sum of its proper divisors (49540454).

71978986 is a wasteful number, since it uses less digits than its factorization.

71978986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2058.

The product of its digits is 1524096, while the sum is 55.

The square root of 71978986 is about 8484.0430220503. The cubic root of 71978986 is about 415.9762876339.

The spelling of 71978986 in words is "seventy-one million, nine hundred seventy-eight thousand, nine hundred eighty-six".