71909966 has 16 divisors (see below), whose sum is σ = 118149840. Its totient is φ = 32672640.

The previous prime is 71909951. The next prime is 71909969. The reversal of 71909966 is 66990917.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 71909966.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (71909969) 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, 35480 + ... + 37451.

It is an arithmetic number, because the mean of its divisors is an integer number (7384365).

Almost surely, 2^71909966 is an apocalyptic number.

71909966 is a deficient number, since it is larger than the sum of its proper divisors (46239874).

71909966 is a wasteful number, since it uses less digits than its factorization.

71909966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72979.

The product of its (nonzero) digits is 183708, while the sum is 47.

The square root of 71909966 is about 8479.9744103387. The cubic root of 71909966 is about 415.8432864777.

The spelling of 71909966 in words is "seventy-one million, nine hundred nine thousand, nine hundred sixty-six".