21870342144 has 624 divisors, whose sum is σ = 77662737152. Its totient is φ = 6019743744.

The previous prime is 21870342113. The next prime is 21870342161. The reversal of 21870342144 is 44124307812.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 21870342099 and 21870342108.

It is a congruent number.

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 47 ways as a sum of consecutive naturals, for example, 299593692 + ... + 299593764.

Almost surely, 2^21870342144 is an apocalyptic number.

21870342144 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 21870342144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38831368576).

21870342144 is an abundant number, since it is smaller than the sum of its proper divisors (55792395008).

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

21870342144 is an frugal number, since it uses more digits than its factorization.

21870342144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162 (or 128 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

Adding to 21870342144 its reverse (44124307812), we get a palindrome (65994649956).

The spelling of 21870342144 in words is "twenty-one billion, eight hundred seventy million, three hundred forty-two thousand, one hundred forty-four".