68121649 has 2 divisors, whose sum is σ = 68121650. Its totient is φ = 68121648.

The previous prime is 68121643. The next prime is 68121679. The reversal of 68121649 is 94612186.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 56731024 + 11390625 = 7532^2 + 3375^2 .

It is a cyclic number.

It is not a de Polignac number, because 68121649 - 2⁵ = 68121617 is a prime.

It is not a weakly prime, because it can be changed into another prime (68121643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34060824 + 34060825.

It is an arithmetic number, because the mean of its divisors is an integer number (34060825).

Almost surely, 2^68121649 is an apocalyptic number.

It is an amenable number.

68121649 is a deficient number, since it is larger than the sum of its proper divisors (1).

68121649 is an equidigital number, since it uses as much as digits as its factorization.

68121649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 20736, while the sum is 37.

The square root of 68121649 is about 8253.5840093865. The cubic root of 68121649 is about 408.4087618906.

The spelling of 68121649 in words is "sixty-eight million, one hundred twenty-one thousand, six hundred forty-nine".