21470239728 has 280 divisors, whose sum is σ = 71560896000. Its totient is φ = 6110163072.

The previous prime is 21470239727. The next prime is 21470239733. The reversal of 21470239728 is 82793207412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21470239727) by changing a digit.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 35843173 + ... + 35843771.

Almost surely, 2^21470239728 is an apocalyptic number.

21470239728 is a gapful number since it is divisible by the number (28) 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 21470239728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35780448000).

21470239728 is an abundant number, since it is smaller than the sum of its proper divisors (50090656272).

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

21470239728 is an equidigital number, since it uses as much as digits as its factorization.

21470239728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1071 (or 1050 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 21470239728 in words is "twenty-one billion, four hundred seventy million, two hundred thirty-nine thousand, seven hundred twenty-eight".