21980817144 has 192 divisors, whose sum is σ = 70300470240. Its totient is φ = 6116705280.

The previous prime is 21980817137. The next prime is 21980817149. The reversal of 21980817144 is 44171808912.

It is a self number, because there is not a number n which added to its sum of digits gives 21980817144.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21980817149) 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 47 ways as a sum of consecutive naturals, for example, 2022894 + ... + 2033730.

Almost surely, 2^21980817144 is an apocalyptic number.

21980817144 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21980817144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35150235120).

21980817144 is an abundant number, since it is smaller than the sum of its proper divisors (48319653096).

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

21980817144 is a wasteful number, since it uses less digits than its factorization.

21980817144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11070 (or 11063 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

It can be divided in two parts, 2198081 and 7144, that added together give a square (2205225 = 1485²).

The spelling of 21980817144 in words is "twenty-one billion, nine hundred eighty million, eight hundred seventeen thousand, one hundred forty-four".