20520385 has 8 divisors (see below), whose sum is σ = 25290216. Its totient is φ = 15972480.

The previous prime is 20520337. The next prime is 20520389. The reversal of 20520385 is 58302502.

It can be written as a sum of positive squares in 4 ways, for example, as 512656 + 20007729 = 716^2 + 4473^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20520385 - 2⁷ = 20520257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20520389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 55276 + ... + 55645.

It is an arithmetic number, because the mean of its divisors is an integer number (3161277).

Almost surely, 2^20520385 is an apocalyptic number.

It is an amenable number.

20520385 is a deficient number, since it is larger than the sum of its proper divisors (4769831).

20520385 is a wasteful number, since it uses less digits than its factorization.

20520385 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110963.

The product of its (nonzero) digits is 2400, while the sum is 25.

The square root of 20520385 is about 4529.9431563762. The cubic root of 20520385 is about 273.7758703128.

Adding to 20520385 its reverse (58302502), we get a palindrome (78822887).

The spelling of 20520385 in words is "twenty million, five hundred twenty thousand, three hundred eighty-five".