68561840 has 40 divisors (see below), whose sum is σ = 163302048. Its totient is φ = 26754560.

The previous prime is 68561797. The next prime is 68561869. The reversal of 68561840 is 4816586.

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 68561794 and 68561803.

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 7 ways as a sum of consecutive naturals, for example, 7172 + ... + 13731.

Almost surely, 2^68561840 is an apocalyptic number.

It is an amenable number.

68561840 is an abundant number, since it is smaller than the sum of its proper divisors (94740208).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

68561840 is a wasteful number, since it uses less digits than its factorization.

68561840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20957 (or 20951 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 38.

The square root of 68561840 is about 8280.2077268629. The cubic root of 68561840 is about 409.2865641574.

The spelling of 68561840 in words is "sixty-eight million, five hundred sixty-one thousand, eight hundred forty".