21709134144 has 168 divisors, whose sum is σ = 62790567840. Its totient is φ = 7171034112.

The previous prime is 21709134143. The next prime is 21709134149. The reversal of 21709134144 is 44143190712.

It is a super-2 number, since 2×21709134144² (a number of 21 digits) contains 22 as substring.

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 = 21709134099 and 21709134108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21709134143) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 51811567 + ... + 51811985.

It is an arithmetic number, because the mean of its divisors is an integer number (373753380).

Almost surely, 2^21709134144 is an apocalyptic number.

21709134144 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 21709134144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31395283920).

21709134144 is an abundant number, since it is smaller than the sum of its proper divisors (41081433696).

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

21709134144 is a wasteful number, since it uses less digits than its factorization.

21709134144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1037 (or 1024 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The spelling of 21709134144 in words is "twenty-one billion, seven hundred nine million, one hundred thirty-four thousand, one hundred forty-four".