71640817 has 16 divisors (see below), whose sum is σ = 76885200. Its totient is φ = 66626560.

The previous prime is 71640797. The next prime is 71640847. The reversal of 71640817 is 71804617.

It can be written as a sum of positive squares in 8 ways, for example, as 474721 + 71166096 = 689^2 + 8436^2 .

It is a cyclic number.

It is not a de Polignac number, because 71640817 - 2⁷ = 71640689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71640847) 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, 105483 + ... + 106159.

It is an arithmetic number, because the mean of its divisors is an integer number (4805325).

Almost surely, 2^71640817 is an apocalyptic number.

It is an amenable number.

71640817 is a deficient number, since it is larger than the sum of its proper divisors (5244383).

71640817 is a wasteful number, since it uses less digits than its factorization.

71640817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 836.

The product of its (nonzero) digits is 9408, while the sum is 34.

The square root of 71640817 is about 8464.0898506573. The cubic root of 71640817 is about 415.3238233192.

The spelling of 71640817 in words is "seventy-one million, six hundred forty thousand, eight hundred seventeen".