20540351 has 4 divisors (see below), whose sum is σ = 22120392. Its totient is φ = 18960312.

The previous prime is 20540341. The next prime is 20540353. The reversal of 20540351 is 15304502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15304502 = 2 ⋅7652251.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20540351 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20540353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 790001 + ... + 790026.

It is an arithmetic number, because the mean of its divisors is an integer number (5530098).

Almost surely, 2^20540351 is an apocalyptic number.

20540351 is a deficient number, since it is larger than the sum of its proper divisors (1580041).

20540351 is a wasteful number, since it uses less digits than its factorization.

20540351 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1580040.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 20540351 is about 4532.1464009893. The cubic root of 20540351 is about 273.8646346828.

Adding to 20540351 its reverse (15304502), we get a palindrome (35844853).

The spelling of 20540351 in words is "twenty million, five hundred forty thousand, three hundred fifty-one".