21338278416 has 800 divisors, whose sum is σ = 83484656640. Its totient is φ = 5100060672.

The previous prime is 21338278411. The next prime is 21338278457. The reversal of 21338278416 is 61487283312.

21338278416 is a `hidden beast` number, since 2 + 1 + 338 + 278 + 41 + 6 = 666.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21338278411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 58142265 + ... + 58142631.

Almost surely, 2^21338278416 is an apocalyptic number.

21338278416 is a gapful number since it is divisible by the number (26) 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 21338278416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41742328320).

21338278416 is an abundant number, since it is smaller than the sum of its proper divisors (62146378224).

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

21338278416 is a wasteful number, since it uses less digits than its factorization.

21338278416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 453 (or 438 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The spelling of 21338278416 in words is "twenty-one billion, three hundred thirty-eight million, two hundred seventy-eight thousand, four hundred sixteen".