21100122144 has 36 divisors (see below), whose sum is σ = 60003473166. Its totient is φ = 7033373952.

The previous prime is 21100122133. The next prime is 21100122163. The reversal of 21100122144 is 44122100112.

It can be written as a sum of positive squares in only one way, i.e., 20857136400 + 242985744 = 144420^2 + 15588^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-3 number, since 3×21100122144³ (a number of 32 digits) contains 333 as substring.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 36631869 + ... + 36632444.

Almost surely, 2^21100122144 is an apocalyptic number.

21100122144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21100122144 is an abundant number, since it is smaller than the sum of its proper divisors (38903351022).

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

21100122144 is a wasteful number, since it uses less digits than its factorization.

21100122144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73264329 (or 73264318 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21100122144 its reverse (44122100112), we get a palindrome (65222222256).

The spelling of 21100122144 in words is "twenty-one billion, one hundred million, one hundred twenty-two thousand, one hundred forty-four".