21345487472 has 40 divisors (see below), whose sum is σ = 42777024000. Its totient is φ = 10307643840.

The previous prime is 21345487451. The next prime is 21345487477. The reversal of 21345487472 is 27478454312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21345487477) 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, 204383 + ... + 290625.

It is an arithmetic number, because the mean of its divisors is an integer number (1069425600).

Almost surely, 2^21345487472 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 21345487472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21388512000).

21345487472 is an abundant number, since it is smaller than the sum of its proper divisors (21431536528).

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

21345487472 is a wasteful number, since it uses less digits than its factorization.

21345487472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86781 (or 86775 counting only the distinct ones).

The product of its digits is 1505280, while the sum is 47.

The spelling of 21345487472 in words is "twenty-one billion, three hundred forty-five million, four hundred eighty-seven thousand, four hundred seventy-two".