20211240042 has 80 divisors (see below), whose sum is σ = 51834796992. Its totient is φ = 5766059520.

The previous prime is 20211240037. The next prime is 20211240061. The reversal of 20211240042 is 24004211202.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20211239997 and 20211240024.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 770698 + ... + 796490.

Almost surely, 2^20211240042 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20211240042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25917398496).

20211240042 is an abundant number, since it is smaller than the sum of its proper divisors (31623556950).

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

20211240042 is a wasteful number, since it uses less digits than its factorization.

20211240042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26505 (or 26496 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

Adding to 20211240042 its reverse (24004211202), we get a palindrome (44215451244).

The spelling of 20211240042 in words is "twenty billion, two hundred eleven million, two hundred forty thousand, forty-two".