20517480 has 48 divisors (see below), whose sum is σ = 66682980. Its totient is φ = 5471232.

The previous prime is 20517479. The next prime is 20517481. The reversal of 20517480 is 8471502.

It is an interprime number because it is at equal distance from previous prime (20517479) and next prime (20517481).

It can be written as a sum of positive squares in 2 ways, for example, as 20304036 + 213444 = 4506^2 + 462^2 .

It is not an unprimeable number, because it can be changed into a prime (20517481) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28137 + ... + 28856.

Almost surely, 2^20517480 is an apocalyptic number.

20517480 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20517480 is an abundant number, since it is smaller than the sum of its proper divisors (46165500).

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

20517480 is a wasteful number, since it uses less digits than its factorization.

20517480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57010 (or 57003 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20517480 is about 4529.6225008272. The cubic root of 20517480 is about 273.7629505351.

Adding to 20517480 its reverse (8471502), we get a palindrome (28988982).

The spelling of 20517480 in words is "twenty million, five hundred seventeen thousand, four hundred eighty".