20553613 has 4 divisors (see below), whose sum is σ = 21031648. Its totient is φ = 20075580.

The previous prime is 20553607. The next prime is 20553619. The reversal of 20553613 is 31635502.

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, and also an emirpimes, since its reverse is a distinct semiprime: 31635502 = 2 ⋅15817751.

It is an interprime number because it is at equal distance from previous prime (20553607) and next prime (20553619).

It is a cyclic number.

It is not a de Polignac number, because 20553613 - 2⁵ = 20553581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20553619) 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, 238953 + ... + 239038.

It is an arithmetic number, because the mean of its divisors is an integer number (5257912).

Almost surely, 2^20553613 is an apocalyptic number.

It is an amenable number.

20553613 is a deficient number, since it is larger than the sum of its proper divisors (478035).

20553613 is an equidigital number, since it uses as much as digits as its factorization.

20553613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478034.

The product of its (nonzero) digits is 2700, while the sum is 25.

The square root of 20553613 is about 4533.6092685630. The cubic root of 20553613 is about 273.9235627799.

The spelling of 20553613 in words is "twenty million, five hundred fifty-three thousand, six hundred thirteen".