121689407 has 4 divisors (see below), whose sum is σ = 139073616. Its totient is φ = 104305200.

The previous prime is 121689401. The next prime is 121689409. The reversal of 121689407 is 704986121.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121689407 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 (121689401) 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, 8692094 + ... + 8692107.

It is an arithmetic number, because the mean of its divisors is an integer number (34768404).

Almost surely, 2^121689407 is an apocalyptic number.

121689407 is a deficient number, since it is larger than the sum of its proper divisors (17384209).

121689407 is an equidigital number, since it uses as much as digits as its factorization.

121689407 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17384208.

The product of its (nonzero) digits is 24192, while the sum is 38.

The square root of 121689407 is about 11031.2921727239. The cubic root of 121689407 is about 495.5463233143.

The spelling of 121689407 in words is "one hundred twenty-one million, six hundred eighty-nine thousand, four hundred seven".