21128277932640 has 960 divisors, whose sum is σ = 80251748438400. Its totient is φ = 5221172183040.

The previous prime is 21128277932569. The next prime is 21128277932683. The reversal of 21128277932640 is 4623977282112.

21128277932640 is a `hidden beast` number, since 2 + 1 + 1 + 2 + 8 + 277 + 9 + 326 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 2657975386 + ... + 2657983334.

It is an arithmetic number, because the mean of its divisors is an integer number (83595571290).

Almost surely, 2^{21128277932640} is an apocalyptic number.

21128277932640 is a gapful number since it is divisible by the number (20) 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 21128277932640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40125874219200).

21128277932640 is an abundant number, since it is smaller than the sum of its proper divisors (59123470505760).

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

21128277932640 is a wasteful number, since it uses less digits than its factorization.

21128277932640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8277 (or 8260 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 54.

The spelling of 21128277932640 in words is "twenty-one trillion, one hundred twenty-eight billion, two hundred seventy-seven million, nine hundred thirty-two thousand, six hundred forty".