20013555 has 16 divisors (see below), whose sum is σ = 33707520. Its totient is φ = 10111968.

The previous prime is 20013547. The next prime is 20013557. The reversal of 20013555 is 55531002.

It is not a de Polignac number, because 20013555 - 2³ = 20013547 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20013557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34827 + ... + 35396.

It is an arithmetic number, because the mean of its divisors is an integer number (2106720).

Almost surely, 2^20013555 is an apocalyptic number.

20013555 is a deficient number, since it is larger than the sum of its proper divisors (13693965).

20013555 is a wasteful number, since it uses less digits than its factorization.

20013555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70250.

The product of its (nonzero) digits is 750, while the sum is 21.

The square root of 20013555 is about 4473.6511933766. The cubic root of 20013555 is about 271.5030710288.

Adding to 20013555 its reverse (55531002), we get a palindrome (75544557).

The spelling of 20013555 in words is "twenty million, thirteen thousand, five hundred fifty-five".