21284093952 has 352 divisors, whose sum is σ = 69655578660. Its totient is φ = 6449725440.

The previous prime is 21284093939. The next prime is 21284093983. The reversal of 21284093952 is 25939048212.

21284093952 is a `hidden beast` number, since 212 + 8 + 40 + 9 + 395 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (352).

It is a junction number, because it is equal to n+sod(n) for n = 21284093898 and 21284093907.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 21 ways as a sum of consecutive naturals, for example, 1934917627 + ... + 1934917637.

Almost surely, 2^21284093952 is an apocalyptic number.

21284093952 is a gapful number since it is divisible by the number (22) 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 21284093952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34827789330).

21284093952 is an abundant number, since it is smaller than the sum of its proper divisors (48371484708).

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

21284093952 is an frugal number, since it uses more digits than its factorization.

21284093952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71 (or 16 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 21284093952 in words is "twenty-one billion, two hundred eighty-four million, ninety-three thousand, nine hundred fifty-two".