20121506 has 16 divisors (see below), whose sum is σ = 32703264. Its totient is φ = 9248064.

The previous prime is 20121467. The next prime is 20121533. The reversal of 20121506 is 60512102.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is an unprimeable number.

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, 5420 + ... + 8343.

It is an arithmetic number, because the mean of its divisors is an integer number (2043954).

Almost surely, 2^20121506 is an apocalyptic number.

20121506 is a deficient number, since it is larger than the sum of its proper divisors (12581758).

20121506 is a wasteful number, since it uses less digits than its factorization.

20121506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13825.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 20121506 is about 4485.7001683126. The cubic root of 20121506 is about 271.9903489223.

Adding to 20121506 its reverse (60512102), we get a palindrome (80633608).

The spelling of 20121506 in words is "twenty million, one hundred twenty-one thousand, five hundred six".