68721904 has 20 divisors (see below), whose sum is σ = 136397520. Its totient is φ = 33522560.

The previous prime is 68721847. The next prime is 68721923. The reversal of 68721904 is 40912786.

It is a congruent number.

It is an unprimeable number.

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, 51724 + ... + 53035.

It is an arithmetic number, because the mean of its divisors is an integer number (6819876).

Almost surely, 2^68721904 is an apocalyptic number.

It is an amenable number.

68721904 is a deficient number, since it is larger than the sum of its proper divisors (67675616).

68721904 is a wasteful number, since it uses less digits than its factorization.

68721904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104808 (or 104802 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 37.

The square root of 68721904 is about 8289.8675502085. The cubic root of 68721904 is about 409.6048224835.

The spelling of 68721904 in words is "sixty-eight million, seven hundred twenty-one thousand, nine hundred four".