20520473 has 4 divisors (see below), whose sum is σ = 20723748. Its totient is φ = 20317200.

The previous prime is 20520433. The next prime is 20520499. The reversal of 20520473 is 37402502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 37402502 = 2 ⋅18701251.

It can be written as a sum of positive squares in 2 ways, for example, as 19465744 + 1054729 = 4412^2 + 1027^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20520473 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20520403) 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, 101486 + ... + 101687.

It is an arithmetic number, because the mean of its divisors is an integer number (5180937).

Almost surely, 2^20520473 is an apocalyptic number.

It is an amenable number.

20520473 is a deficient number, since it is larger than the sum of its proper divisors (203275).

20520473 is a wasteful number, since it uses less digits than its factorization.

20520473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 203274.

The product of its (nonzero) digits is 1680, while the sum is 23.

The square root of 20520473 is about 4529.9528695120. The cubic root of 20520473 is about 273.7762616674.

Adding to 20520473 its reverse (37402502), we get a palindrome (57922975).

The spelling of 20520473 in words is "twenty million, five hundred twenty thousand, four hundred seventy-three".