21273452928 has 1024 divisors, whose sum is σ = 85871923200. Its totient is φ = 5021761536.

The previous prime is 21273452873. The next prime is 21273452933. The reversal of 21273452928 is 82925437212.

21273452928 is a `hidden beast` number, since 2 + 12 + 7 + 345 + 292 + 8 = 666.

Its product of digits (483840) is a multiple of the sum of its prime factors (256).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 122967850 + ... + 122968022.

It is an arithmetic number, because the mean of its divisors is an integer number (83859300).

Almost surely, 2^21273452928 is an apocalyptic number.

21273452928 is a gapful number since it is divisible by the number (28) 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 21273452928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42935961600).

21273452928 is an abundant number, since it is smaller than the sum of its proper divisors (64598470272).

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

21273452928 is a wasteful number, since it uses less digits than its factorization.

21273452928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 238 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The spelling of 21273452928 in words is "twenty-one billion, two hundred seventy-three million, four hundred fifty-two thousand, nine hundred twenty-eight".