20105577 has 48 divisors (see below), whose sum is σ = 33126912. Its totient is φ = 12130560.

The previous prime is 20105573. The next prime is 20105597. The reversal of 20105577 is 77550102.

It is not a de Polignac number, because 20105577 - 2² = 20105573 is a prime.

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

It is a self number, because there is not a number n which added to its sum of digits gives 20105577.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20105573) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 127983 + ... + 128139.

It is an arithmetic number, because the mean of its divisors is an integer number (690144).

Almost surely, 2^20105577 is an apocalyptic number.

20105577 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20105577 is a deficient number, since it is larger than the sum of its proper divisors (13021335).

20105577 is a wasteful number, since it uses less digits than its factorization.

20105577 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220 (or 208 counting only the distinct ones).

The product of its (nonzero) digits is 2450, while the sum is 27.

The square root of 20105577 is about 4483.9242857122. The cubic root of 20105577 is about 271.9185571117.

Adding to 20105577 its reverse (77550102), we get a palindrome (97655679).

The spelling of 20105577 in words is "twenty million, one hundred five thousand, five hundred seventy-seven".