68051561 has 4 divisors (see below), whose sum is σ = 72054612. Its totient is φ = 64048512.

The previous prime is 68051551. The next prime is 68051591. The reversal of 68051561 is 16515086.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 60543961 + 7507600 = 7781^2 + 2740^2 .

It is a cyclic number.

It is not a de Polignac number, because 68051561 - 2¹⁸ = 67789417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68051551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2001500 + ... + 2001533.

It is an arithmetic number, because the mean of its divisors is an integer number (18013653).

Almost surely, 2^68051561 is an apocalyptic number.

It is an amenable number.

68051561 is a deficient number, since it is larger than the sum of its proper divisors (4003051).

68051561 is a wasteful number, since it uses less digits than its factorization.

68051561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4003050.

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 68051561 is about 8249.3370036628. The cubic root of 68051561 is about 408.2686479608.

The spelling of 68051561 in words is "sixty-eight million, fifty-one thousand, five hundred sixty-one".