20121445 has 4 divisors (see below), whose sum is σ = 24145740. Its totient is φ = 16097152.

The previous prime is 20121433. The next prime is 20121467. The reversal of 20121445 is 54412102.

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

It can be written as a sum of positive squares in 2 ways, for example, as 2024929 + 18096516 = 1423^2 + 4254^2 .

It is a cyclic number.

It is not a de Polignac number, because 20121445 - 2¹³ = 20113253 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2012140 + ... + 2012149.

It is an arithmetic number, because the mean of its divisors is an integer number (6036435).

Almost surely, 2^20121445 is an apocalyptic number.

It is an amenable number.

20121445 is a deficient number, since it is larger than the sum of its proper divisors (4024295).

20121445 is an equidigital number, since it uses as much as digits as its factorization.

20121445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4024294.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 20121445 is about 4485.6933689230. The cubic root of 20121445 is about 271.9900740683.

Adding to 20121445 its reverse (54412102), we get a palindrome (74533547).

The spelling of 20121445 in words is "twenty million, one hundred twenty-one thousand, four hundred forty-five".