21709490832 has 80 divisors (see below), whose sum is σ = 62471735680. Its totient is φ = 7218211968.

The previous prime is 21709490827. The next prime is 21709490833. The reversal of 21709490832 is 23809490712.

It is not an unprimeable number, because it can be changed into a prime (21709490833) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108213 + ... + 234795.

It is an arithmetic number, because the mean of its divisors is an integer number (780896696).

Almost surely, 2^21709490832 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 21709490832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31235867840).

21709490832 is an abundant number, since it is smaller than the sum of its proper divisors (40762244848).

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

21709490832 is a wasteful number, since it uses less digits than its factorization.

21709490832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126997 (or 126985 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 45.

The spelling of 21709490832 in words is "twenty-one billion, seven hundred nine million, four hundred ninety thousand, eight hundred thirty-two".