68640571 has 2 divisors, whose sum is σ = 68640572. Its totient is φ = 68640570.

The previous prime is 68640547. The next prime is 68640581. The reversal of 68640571 is 17504686.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 68640571 - 2⁷ = 68640443 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 68640571.

It is not a weakly prime, because it can be changed into another prime (68640511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34320285 + 34320286.

It is an arithmetic number, because the mean of its divisors is an integer number (34320286).

Almost surely, 2^68640571 is an apocalyptic number.

68640571 is a deficient number, since it is larger than the sum of its proper divisors (1).

68640571 is an equidigital number, since it uses as much as digits as its factorization.

68640571 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 68640571 is about 8284.9605309863. The cubic root of 68640571 is about 409.4431683463.

The spelling of 68640571 in words is "sixty-eight million, six hundred forty thousand, five hundred seventy-one".