20780553 has 4 divisors (see below), whose sum is σ = 27707408. Its totient is φ = 13853700.

The previous prime is 20780549. The next prime is 20780581. The reversal of 20780553 is 35508702.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 20780553 - 2² = 20780549 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20780553.

It is not an unprimeable number, because it can be changed into a prime (20780453) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 3463423 + ... + 3463428.

It is an arithmetic number, because the mean of its divisors is an integer number (6926852).

Almost surely, 2^20780553 is an apocalyptic number.

It is an amenable number.

20780553 is a deficient number, since it is larger than the sum of its proper divisors (6926855).

20780553 is an equidigital number, since it uses as much as digits as its factorization.

20780553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6926854.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 20780553 is about 4558.5691834171. The cubic root of 20780553 is about 274.9280384711.

The spelling of 20780553 in words is "twenty million, seven hundred eighty thousand, five hundred fifty-three".