20122145 has 4 divisors (see below), whose sum is σ = 24146580. Its totient is φ = 16097712.

The previous prime is 20122133. The next prime is 20122147. The reversal of 20122145 is 54122102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54122102 = 2 ⋅27061051.

It can be written as a sum of positive squares in 2 ways, for example, as 2085136 + 18037009 = 1444^2 + 4247^2 .

It is a cyclic number.

It is not a de Polignac number, because 20122145 - 2¹⁰ = 20121121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20122147) 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, 2012210 + ... + 2012219.

It is an arithmetic number, because the mean of its divisors is an integer number (6036645).

Almost surely, 2^20122145 is an apocalyptic number.

It is an amenable number.

20122145 is a deficient number, since it is larger than the sum of its proper divisors (4024435).

20122145 is an equidigital number, since it uses as much as digits as its factorization.

20122145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4024434.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 20122145 is about 4485.7713940860. The cubic root of 20122145 is about 271.9932280970.

Adding to 20122145 its reverse (54122102), we get a palindrome (74244247).

The spelling of 20122145 in words is "twenty million, one hundred twenty-two thousand, one hundred forty-five".