20513655 has 20 divisors (see below), whose sum is σ = 36773352. Its totient is φ = 10940400.

The previous prime is 20513641. The next prime is 20513659. The reversal of 20513655 is 55631502.

20513655 is a `hidden beast` number, since 2 + 0 + 5 + 1 + 3 + 655 = 666.

It is not a de Polignac number, because 20513655 - 2⁴ = 20513639 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20513659) 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 19 ways as a sum of consecutive naturals, for example, 24921 + ... + 25730.

Almost surely, 2^20513655 is an apocalyptic number.

20513655 is a deficient number, since it is larger than the sum of its proper divisors (16259697).

20513655 is an equidigital number, since it uses as much as digits as its factorization.

20513655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50668 (or 50659 counting only the distinct ones).

The product of its (nonzero) digits is 4500, while the sum is 27.

The square root of 20513655 is about 4529.2002605317. The cubic root of 20513655 is about 273.7459372638.

The spelling of 20513655 in words is "twenty million, five hundred thirteen thousand, six hundred fifty-five".