20561480 has 32 divisors (see below), whose sum is σ = 46683000. Its totient is φ = 8150016.

The previous prime is 20561473. The next prime is 20561491. The reversal of 20561480 is 8416502.

It can be written as a sum of positive squares in 4 ways, for example, as 12687844 + 7873636 = 3562^2 + 2806^2 .

It is an unprimeable number.

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 in 7 ways as a sum of consecutive naturals, for example, 2246 + ... + 6794.

Almost surely, 2^20561480 is an apocalyptic number.

20561480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20561480 is an abundant number, since it is smaller than the sum of its proper divisors (26121520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20561480 is a wasteful number, since it uses less digits than its factorization.

20561480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4673 (or 4669 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 20561480 is about 4534.4768165688. The cubic root of 20561480 is about 273.9585068679.

Adding to 20561480 its reverse (8416502), we get a palindrome (28977982).

The spelling of 20561480 in words is "twenty million, five hundred sixty-one thousand, four hundred eighty".