68409890 has 8 divisors (see below), whose sum is σ = 123137820. Its totient is φ = 27363952.

The previous prime is 68409883. The next prime is 68409893. The reversal of 68409890 is 9890486.

It can be written as a sum of positive squares in 2 ways, for example, as 65237929 + 3171961 = 8077^2 + 1781^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (68409893) 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 3 ways as a sum of consecutive naturals, for example, 3420485 + ... + 3420504.

Almost surely, 2^68409890 is an apocalyptic number.

68409890 is a deficient number, since it is larger than the sum of its proper divisors (54727930).

68409890 is a wasteful number, since it uses less digits than its factorization.

68409890 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6840996.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 68409890 is about 8271.0271429853. The cubic root of 68409890 is about 408.9839804184.

The spelling of 68409890 in words is "sixty-eight million, four hundred nine thousand, eight hundred ninety".