21047448020 has 24 divisors (see below), whose sum is σ = 44696269800. Its totient is φ = 8324383232.

The previous prime is 21047448017. The next prime is 21047448029. The reversal of 21047448020 is 2084474012.

It can be written as a sum of positive squares in 4 ways, for example, as 1145010244 + 19902437776 = 33838^2 + 141076^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21047448029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5910425 + ... + 5913984.

It is an arithmetic number, because the mean of its divisors is an integer number (1862344575).

Almost surely, 2^21047448020 is an apocalyptic number.

21047448020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21047448020 is an abundant number, since it is smaller than the sum of its proper divisors (23648821780).

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

21047448020 is a wasteful number, since it uses less digits than its factorization.

21047448020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11824507 (or 11824505 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 32.

The spelling of 21047448020 in words is "twenty-one billion, forty-seven million, four hundred forty-eight thousand, twenty".