68640651 has 24 divisors (see below), whose sum is σ = 103896000. Its totient is φ = 43610112.

The previous prime is 68640647. The next prime is 68640653. The reversal of 68640651 is 15604686.

68640651 is a `hidden beast` number, since 6 + 8 + 640 + 6 + 5 + 1 = 666.

It is not a de Polignac number, because 68640651 - 2² = 68640647 is a prime.

It is not an unprimeable number, because it can be changed into a prime (68640653) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18955 + ... + 22283.

It is an arithmetic number, because the mean of its divisors is an integer number (4329000).

Almost surely, 2^68640651 is an apocalyptic number.

68640651 is a deficient number, since it is larger than the sum of its proper divisors (35255349).

68640651 is a wasteful number, since it uses less digits than its factorization.

68640651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3443 (or 3440 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 68640651 is about 8284.9653590103. The cubic root of 68640651 is about 409.4433274137.

The spelling of 68640651 in words is "sixty-eight million, six hundred forty thousand, six hundred fifty-one".