68515861 has 2 divisors, whose sum is σ = 68515862. Its totient is φ = 68515860.

The previous prime is 68515847. The next prime is 68515901. The reversal of 68515861 is 16851586.

It is an a-pointer prime, because the next prime (68515901) can be obtained adding 68515861 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64883025 + 3632836 = 8055^2 + 1906^2 .

It is a cyclic number.

It is not a de Polignac number, because 68515861 - 2²⁵ = 34961429 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68515841) 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 as a sum of consecutive naturals, namely, 34257930 + 34257931.

It is an arithmetic number, because the mean of its divisors is an integer number (34257931).

Almost surely, 2^68515861 is an apocalyptic number.

It is an amenable number.

68515861 is a deficient number, since it is larger than the sum of its proper divisors (1).

68515861 is an equidigital number, since it uses as much as digits as its factorization.

68515861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 57600, while the sum is 40.

The square root of 68515861 is about 8277.4308212150. The cubic root of 68515861 is about 409.1950516619.

The spelling of 68515861 in words is "sixty-eight million, five hundred fifteen thousand, eight hundred sixty-one".