20506456 has 8 divisors (see below), whose sum is σ = 38449620. Its totient is φ = 10253224.

The previous prime is 20506441. The next prime is 20506459. The reversal of 20506456 is 65460502.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20506459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1281646 + ... + 1281661.

Almost surely, 2^20506456 is an apocalyptic number.

It is an amenable number.

20506456 is a deficient number, since it is larger than the sum of its proper divisors (17943164).

20506456 is a wasteful number, since it uses less digits than its factorization.

20506456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2563313 (or 2563309 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 28.

The square root of 20506456 is about 4528.4054588784. The cubic root of 20506456 is about 273.7139109935.

Adding to 20506456 its reverse (65460502), we get a palindrome (85966958).

It can be divided in two parts, 205064 and 56, that added together give a triangular number (205120 = T₆₄₀).

The spelling of 20506456 in words is "twenty million, five hundred six thousand, four hundred fifty-six".