20123636 has 12 divisors (see below), whose sum is σ = 37925412. Its totient is φ = 9287808.

The previous prime is 20123633. The next prime is 20123659. The reversal of 20123636 is 63632102.

It can be written as a sum of positive squares in 2 ways, for example, as 7873636 + 12250000 = 2806^2 + 3500^2 .

20123636 is a modest number, since divided by 3636 gives 2012 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123633) 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, 193445 + ... + 193548.

It is an arithmetic number, because the mean of its divisors is an integer number (3160451).

Almost surely, 2^20123636 is an apocalyptic number.

20123636 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is an amenable number.

20123636 is a deficient number, since it is larger than the sum of its proper divisors (17801776).

20123636 is a wasteful number, since it uses less digits than its factorization.

20123636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387010 (or 387008 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 23.

The square root of 20123636 is about 4485.9375831592. The cubic root of 20123636 is about 271.9999459342. Note that the first 4 decimals are identical.

Adding to 20123636 its reverse (63632102), we get a palindrome (83755738).

The spelling of 20123636 in words is "twenty million, one hundred twenty-three thousand, six hundred thirty-six".