21737929680 has 240 divisors, whose sum is σ = 73763778816. Its totient is φ = 5736775680.

The previous prime is 21737929673. The next prime is 21737929691. The reversal of 21737929680 is 8692973712.

It is a tau number, because it is divible by the number of its divisors (240).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 43216309 + ... + 43216811.

Almost surely, 2^21737929680 is an apocalyptic number.

21737929680 is a gapful number since it is divisible by the number (20) 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 21737929680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36881889408).

21737929680 is an abundant number, since it is smaller than the sum of its proper divisors (52025849136).

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

21737929680 is a wasteful number, since it uses less digits than its factorization.

21737929680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1026 (or 1017 counting only the distinct ones).

The product of its (nonzero) digits is 2286144, while the sum is 54.

The spelling of 21737929680 in words is "twenty-one billion, seven hundred thirty-seven million, nine hundred twenty-nine thousand, six hundred eighty".