21704125072 has 60 divisors (see below), whose sum is σ = 49149543216. Its totient is φ = 9257613120.

The previous prime is 21704125057. The next prime is 21704125073. The reversal of 21704125072 is 27052140712.

It is not an unprimeable number, because it can be changed into a prime (21704125073) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 99823 + ... + 231025.

Almost surely, 2^21704125072 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21704125072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24574771608).

21704125072 is an abundant number, since it is smaller than the sum of its proper divisors (27445418144).

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

21704125072 is a wasteful number, since it uses less digits than its factorization.

21704125072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131436 (or 131423 counting only the distinct ones).

The product of its (nonzero) digits is 7840, while the sum is 31.

Adding to 21704125072 its reverse (27052140712), we get a palindrome (48756265784).

The spelling of 21704125072 in words is "twenty-one billion, seven hundred four million, one hundred twenty-five thousand, seventy-two".