20413555 has 4 divisors (see below), whose sum is σ = 24496272. Its totient is φ = 16330840.

The previous prime is 20413537. The next prime is 20413559. The reversal of 20413555 is 55531402.

It is a semiprime because it is the product of two primes.

It is a de Polignac number, because none of the positive numbers 2^k-20413555 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20413559) 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, 2041351 + ... + 2041360.

It is an arithmetic number, because the mean of its divisors is an integer number (6124068).

Almost surely, 2^20413555 is an apocalyptic number.

20413555 is a deficient number, since it is larger than the sum of its proper divisors (4082717).

20413555 is an equidigital number, since it uses as much as digits as its factorization.

20413555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4082716.

The product of its (nonzero) digits is 3000, while the sum is 25.

The square root of 20413555 is about 4518.1362307925. The cubic root of 20413555 is about 273.2999471748.

Adding to 20413555 its reverse (55531402), we get a palindrome (75944957).

The spelling of 20413555 in words is "twenty million, four hundred thirteen thousand, five hundred fifty-five".