20535553 has 4 divisors (see below), whose sum is σ = 21013168. Its totient is φ = 20057940.

The previous prime is 20535551. The next prime is 20535583. The reversal of 20535553 is 35553502.

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 a cyclic number.

It is not a de Polignac number, because 20535553 - 2¹ = 20535551 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20535551) 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, 238743 + ... + 238828.

It is an arithmetic number, because the mean of its divisors is an integer number (5253292).

Almost surely, 2^20535553 is an apocalyptic number.

It is an amenable number.

20535553 is a deficient number, since it is larger than the sum of its proper divisors (477615).

20535553 is an equidigital number, since it uses as much as digits as its factorization.

20535553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 477614.

The product of its (nonzero) digits is 11250, while the sum is 28.

The square root of 20535553 is about 4531.6170403069. The cubic root of 20535553 is about 273.8433091004.

The spelling of 20535553 in words is "twenty million, five hundred thirty-five thousand, five hundred fifty-three".