20121351 has 4 divisors (see below), whose sum is σ = 26828472. Its totient is φ = 13414232.

The previous prime is 20121349. The next prime is 20121391. The reversal of 20121351 is 15312102.

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

It is a cyclic number.

It is not a de Polignac number, because 20121351 - 2¹ = 20121349 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20121351.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20121391) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 3353556 + ... + 3353561.

It is an arithmetic number, because the mean of its divisors is an integer number (6707118).

Almost surely, 2^20121351 is an apocalyptic number.

20121351 is a deficient number, since it is larger than the sum of its proper divisors (6707121).

20121351 is an equidigital number, since it uses as much as digits as its factorization.

20121351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6707120.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 20121351 is about 4485.6828911549. The cubic root of 20121351 is about 271.9896505217.

Adding to 20121351 its reverse (15312102), we get a palindrome (35433453).

Subtracting from 20121351 its reverse (15312102), we obtain a square (4809249 = 2193²).

The spelling of 20121351 in words is "twenty million, one hundred twenty-one thousand, three hundred fifty-one".