20105049690 has 384 divisors, whose sum is σ = 64308142080. Its totient is φ = 4464979200.

The previous prime is 20105049661. The next prime is 20105049697. The reversal of 20105049690 is 9694050102.

20105049690 is a `hidden beast` number, since 20 + 10 + 50 + 496 + 90 = 666.

It is a super-2 number, since 2×20105049690² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20105049697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 15743332 + ... + 15744608.

It is an arithmetic number, because the mean of its divisors is an integer number (167469120).

Almost surely, 2^20105049690 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20105049690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32154071040).

20105049690 is an abundant number, since it is smaller than the sum of its proper divisors (44203092390).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20105049690 is a wasteful number, since it uses less digits than its factorization.

20105049690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1360 (or 1348 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

Adding to 20105049690 its reverse (9694050102), we get a palindrome (29799099792).

The spelling of 20105049690 in words is "twenty billion, one hundred five million, forty-nine thousand, six hundred ninety".