20124689 has 12 divisors (see below), whose sum is σ = 21940236. Its totient is φ = 18450432.

The previous prime is 20124661. The next prime is 20124733. The reversal of 20124689 is 98642102.

20124689 = T₁₆₂ + T₁₆₃ + ... + T₄₉₉.

It can be written as a sum of positive squares in 6 ways, for example, as 11022400 + 9102289 = 3320^2 + 3017^2 .

It is a de Polignac number, because none of the positive numbers 2^k-20124689 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 (20124619) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32309 + ... + 32925.

It is an arithmetic number, because the mean of its divisors is an integer number (1828353).

Almost surely, 2^20124689 is an apocalyptic number.

It is an amenable number.

20124689 is a deficient number, since it is larger than the sum of its proper divisors (1815547).

20124689 is a wasteful number, since it uses less digits than its factorization.

20124689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 836 (or 823 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 20124689 is about 4486.0549483929. The cubic root of 20124689 is about 272.0046901224.

The spelling of 20124689 in words is "twenty million, one hundred twenty-four thousand, six hundred eighty-nine".