21277347456 has 128 divisors (see below), whose sum is σ = 57028608000. Its totient is φ = 7028702208.

The previous prime is 21277347439. The next prime is 21277347479. The reversal of 21277347456 is 65474377212.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29266965 + ... + 29267691.

It is an arithmetic number, because the mean of its divisors is an integer number (445536000).

Almost surely, 2^21277347456 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 21277347456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28514304000).

21277347456 is an abundant number, since it is smaller than the sum of its proper divisors (35751260544).

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

21277347456 is a wasteful number, since it uses less digits than its factorization.

21277347456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326 (or 1314 counting only the distinct ones).

The product of its digits is 1975680, while the sum is 48.

The spelling of 21277347456 in words is "twenty-one billion, two hundred seventy-seven million, three hundred forty-seven thousand, four hundred fifty-six".