21371247472 has 20 divisors (see below), whose sum is σ = 42834613320. Its totient is φ = 10317153728.

The previous prime is 21371247461. The next prime is 21371247473. The reversal of 21371247472 is 27474217312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371247473) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23028898 + ... + 23029825.

It is an arithmetic number, because the mean of its divisors is an integer number (2141730666).

Almost surely, 2^21371247472 is an apocalyptic number.

It is an amenable number.

21371247472 is an abundant number, since it is smaller than the sum of its proper divisors (21463365848).

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

21371247472 is a wasteful number, since it uses less digits than its factorization.

21371247472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46058760 (or 46058754 counting only the distinct ones).

The product of its digits is 131712, while the sum is 40.

The spelling of 21371247472 in words is "twenty-one billion, three hundred seventy-one million, two hundred forty-seven thousand, four hundred seventy-two".