20551553 has 8 divisors (see below), whose sum is σ = 22570176. Its totient is φ = 18558000.

The previous prime is 20551523. The next prime is 20551561. The reversal of 20551553 is 35515502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20551553 - 2¹⁰ = 20550529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20551523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4526 + ... + 7847.

It is an arithmetic number, because the mean of its divisors is an integer number (2821272).

Almost surely, 2^20551553 is an apocalyptic number.

It is an amenable number.

20551553 is a deficient number, since it is larger than the sum of its proper divisors (2018623).

20551553 is a wasteful number, since it uses less digits than its factorization.

20551553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12535.

The product of its (nonzero) digits is 3750, while the sum is 26.

The square root of 20551553 is about 4533.3820708164. The cubic root of 20551553 is about 273.9144110816.

The spelling of 20551553 in words is "twenty million, five hundred fifty-one thousand, five hundred fifty-three".