68404681 has 2 divisors, whose sum is σ = 68404682. Its totient is φ = 68404680.

The previous prime is 68404657. The next prime is 68404711. The reversal of 68404681 is 18640486.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68211081 + 193600 = 8259^2 + 440^2 .

It is a cyclic number.

It is not a de Polignac number, because 68404681 - 2²¹ = 66307529 is a prime.

It is a super-2 number, since 2×68404681² = 9358400765423522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 68404681.

It is not a weakly prime, because it can be changed into another prime (68404621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34202340 + 34202341.

It is an arithmetic number, because the mean of its divisors is an integer number (34202341).

Almost surely, 2^68404681 is an apocalyptic number.

It is an amenable number.

68404681 is a deficient number, since it is larger than the sum of its proper divisors (1).

68404681 is an equidigital number, since it uses as much as digits as its factorization.

68404681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 36864, while the sum is 37.

The square root of 68404681 is about 8270.7122426064. The cubic root of 68404681 is about 408.9735996015.

The spelling of 68404681 in words is "sixty-eight million, four hundred four thousand, six hundred eighty-one".