688820261 has 8 divisors (see below), whose sum is σ = 722180544. Its totient is φ = 655744320.

The previous prime is 688820239. The next prime is 688820269. The reversal of 688820261 is 162028886.

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

It is a cyclic number.

It is not a de Polignac number, because 688820261 - 2²⁶ = 621711397 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 (688820269) 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 7 ways as a sum of consecutive naturals, for example, 66116 + ... + 75821.

It is an arithmetic number, because the mean of its divisors is an integer number (90272568).

Almost surely, 2^688820261 is an apocalyptic number.

It is an amenable number.

688820261 is a deficient number, since it is larger than the sum of its proper divisors (33360283).

688820261 is a wasteful number, since it uses less digits than its factorization.

688820261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142171.

The product of its (nonzero) digits is 73728, while the sum is 41.

The square root of 688820261 is about 26245.3855182202. The cubic root of 688820261 is about 883.1516899873.

The spelling of 688820261 in words is "six hundred eighty-eight million, eight hundred twenty thousand, two hundred sixty-one".