689420921 has 16 divisors (see below), whose sum is σ = 797232384. Its totient is φ = 583965504.

The previous prime is 689420917. The next prime is 689420939. The reversal of 689420921 is 129024986.

It is not a de Polignac number, because 689420921 - 2² = 689420917 is a prime.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (689420911) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 556715 + ... + 557951.

It is an arithmetic number, because the mean of its divisors is an integer number (49827024).

Almost surely, 2^689420921 is an apocalyptic number.

It is an amenable number.

689420921 is a deficient number, since it is larger than the sum of its proper divisors (107811463).

689420921 is a wasteful number, since it uses less digits than its factorization.

689420921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2120.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 689420921 is about 26256.8261791101. The cubic root of 689420921 is about 883.4083218962.

The spelling of 689420921 in words is "six hundred eighty-nine million, four hundred twenty thousand, nine hundred twenty-one".