20506384 has 10 divisors (see below), whose sum is σ = 39731150. Its totient is φ = 10253184.

The previous prime is 20506351. The next prime is 20506391. The reversal of 20506384 is 48360502.

It can be written as a sum of positive squares in only one way, i.e., 20502784 + 3600 = 4528^2 + 60^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 640809 + ... + 640840.

It is an arithmetic number, because the mean of its divisors is an integer number (3973115).

Almost surely, 2^20506384 is an apocalyptic number.

It is an amenable number.

20506384 is a deficient number, since it is larger than the sum of its proper divisors (19224766).

20506384 is a wasteful number, since it uses less digits than its factorization.

20506384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1281657 (or 1281651 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 20506384 is about 4528.3975090533. The cubic root of 20506384 is about 273.7135906485.

Adding to 20506384 its reverse (48360502), we get a palindrome (68866886).

The spelling of 20506384 in words is "twenty million, five hundred six thousand, three hundred eighty-four".