68735781 has 12 divisors (see below), whose sum is σ = 99403980. Its totient is φ = 45768960.

The previous prime is 68735759. The next prime is 68735783. The reversal of 68735781 is 18753786.

68735781 is a `hidden beast` number, since 6 + 8 + 73 + 578 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 30802500 + 37933281 = 5550^2 + 6159^2 .

It is not a de Polignac number, because 68735781 - 2⁶ = 68735717 is a prime.

It is a super-2 number, since 2×68735781² = 9449215179359922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68735783) 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 11 ways as a sum of consecutive naturals, for example, 4251 + ... + 12471.

It is an arithmetic number, because the mean of its divisors is an integer number (8283665).

Almost surely, 2^68735781 is an apocalyptic number.

It is an amenable number.

68735781 is a deficient number, since it is larger than the sum of its proper divisors (30668199).

68735781 is a wasteful number, since it uses less digits than its factorization.

68735781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9156 (or 9153 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 68735781 is about 8290.7044935880. The cubic root of 68735781 is about 409.6323911006.

The spelling of 68735781 in words is "sixty-eight million, seven hundred thirty-five thousand, seven hundred eighty-one".