20121550 has 24 divisors (see below), whose sum is σ = 39055536. Its totient is φ = 7698240.

The previous prime is 20121539. The next prime is 20121559. The reversal of 20121550 is 5512102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7599 + ... + 9898.

It is an arithmetic number, because the mean of its divisors is an integer number (1627314).

Almost surely, 2^20121550 is an apocalyptic number.

20121550 is a deficient number, since it is larger than the sum of its proper divisors (18933986).

20121550 is a wasteful number, since it uses less digits than its factorization.

20121550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17532 (or 17527 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 16.

The square root of 20121550 is about 4485.7050727840. The cubic root of 20121550 is about 271.9905471773.

Adding to 20121550 its reverse (5512102), we get a palindrome (25633652).

The spelling of 20121550 in words is "twenty million, one hundred twenty-one thousand, five hundred fifty".