20516155 has 12 divisors (see below), whose sum is σ = 27061776. Its totient is φ = 14920400.

The previous prime is 20516149. The next prime is 20516173. The reversal of 20516155 is 55161502.

It is not a de Polignac number, because 20516155 - 2³ = 20516147 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 16351 + ... + 17560.

It is an arithmetic number, because the mean of its divisors is an integer number (2255148).

Almost surely, 2^20516155 is an apocalyptic number.

20516155 is a deficient number, since it is larger than the sum of its proper divisors (6545621).

20516155 is a wasteful number, since it uses less digits than its factorization.

20516155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33938 (or 33927 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 20516155 is about 4529.4762390369. The cubic root of 20516155 is about 273.7570572884.

Adding to 20516155 its reverse (55161502), we get a palindrome (75677657).

The spelling of 20516155 in words is "twenty million, five hundred sixteen thousand, one hundred fifty-five".