20280553 has 4 divisors (see below), whose sum is σ = 20367828. Its totient is φ = 20193280.

The previous prime is 20280529. The next prime is 20280569. The reversal of 20280553 is 35508202.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35508202 = 2 ⋅17754101.

It can be written as a sum of positive squares in 2 ways, for example, as 14462809 + 5817744 = 3803^2 + 2412^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20280553 is a prime.

It is a super-2 number, since 2×20280553² = 822601659971618, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20280523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 43288 + ... + 43753.

It is an arithmetic number, because the mean of its divisors is an integer number (5091957).

Almost surely, 2^20280553 is an apocalyptic number.

It is an amenable number.

20280553 is a deficient number, since it is larger than the sum of its proper divisors (87275).

20280553 is an equidigital number, since it uses as much as digits as its factorization.

20280553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87274.

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

The square root of 20280553 is about 4503.3934982411. The cubic root of 20280553 is about 272.7051027197.

Adding to 20280553 its reverse (35508202), we get a palindrome (55788755).

The spelling of 20280553 in words is "twenty million, two hundred eighty thousand, five hundred fifty-three".