68071561 has 4 divisors (see below), whose sum is σ = 68836500. Its totient is φ = 67306624.

The previous prime is 68071489. The next prime is 68071583. The reversal of 68071561 is 16517086.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16517086 = 2 ⋅8258543.

It can be written as a sum of positive squares in 2 ways, for example, as 6150400 + 61921161 = 2480^2 + 7869^2 .

It is a cyclic number.

It is not a de Polignac number, because 68071561 - 2⁹ = 68071049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68071261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 382336 + ... + 382513.

It is an arithmetic number, because the mean of its divisors is an integer number (17209125).

Almost surely, 2^68071561 is an apocalyptic number.

It is an amenable number.

68071561 is a deficient number, since it is larger than the sum of its proper divisors (764939).

68071561 is an equidigital number, since it uses as much as digits as its factorization.

68071561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764938.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 68071561 is about 8250.5491332396. The cubic root of 68071561 is about 408.3086400542.

The spelling of 68071561 in words is "sixty-eight million, seventy-one thousand, five hundred sixty-one".