20101978944 has 84 divisors (see below), whose sum is σ = 58430342880. Its totient is φ = 6606270720.

The previous prime is 20101978943. The next prime is 20101978993. The reversal of 20101978944 is 44987910102.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20101978944.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20101978943) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 204874 + ... + 286665.

It is an arithmetic number, because the mean of its divisors is an integer number (695599320).

Almost surely, 2^20101978944 is an apocalyptic number.

20101978944 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20101978944 is an abundant number, since it is smaller than the sum of its proper divisors (38328363936).

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

20101978944 is a wasteful number, since it uses less digits than its factorization.

20101978944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 491628 (or 491615 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 45.

The spelling of 20101978944 in words is "twenty billion, one hundred one million, nine hundred seventy-eight thousand, nine hundred forty-four".