68755991 has 4 divisors (see below), whose sum is σ = 69626400. Its totient is φ = 67885584.

The previous prime is 68755979. The next prime is 68756021. The reversal of 68755991 is 19955786.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 68755991 - 2¹⁴ = 68739607 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68755961) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 435086 + ... + 435243.

It is an arithmetic number, because the mean of its divisors is an integer number (17406600).

Almost surely, 2^68755991 is an apocalyptic number.

68755991 is a deficient number, since it is larger than the sum of its proper divisors (870409).

68755991 is an equidigital number, since it uses as much as digits as its factorization.

68755991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870408.

The product of its digits is 680400, while the sum is 50.

The square root of 68755991 is about 8291.9232389115. The cubic root of 68755991 is about 409.6725344789.

The spelling of 68755991 in words is "sixty-eight million, seven hundred fifty-five thousand, nine hundred ninety-one".