68137940 has 24 divisors (see below), whose sum is σ = 154097160. Its totient is φ = 25158528.

The previous prime is 68137931. The next prime is 68137957. The reversal of 68137940 is 4973186.

It can be written as a sum of positive squares in 4 ways, for example, as 42436 + 68095504 = 206^2 + 8252^2 .

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 68137894 and 68137903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130775 + ... + 131294.

It is an arithmetic number, because the mean of its divisors is an integer number (6420715).

Almost surely, 2^68137940 is an apocalyptic number.

It is an amenable number.

68137940 is an abundant number, since it is smaller than the sum of its proper divisors (85959220).

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

68137940 is a wasteful number, since it uses less digits than its factorization.

68137940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 262091 (or 262089 counting only the distinct ones).

The product of its (nonzero) digits is 36288, while the sum is 38.

The square root of 68137940 is about 8254.5708549870. The cubic root of 68137940 is about 408.4413156966.

The spelling of 68137940 in words is "sixty-eight million, one hundred thirty-seven thousand, nine hundred forty".