21348387648 has 224 divisors, whose sum is σ = 72904421120. Its totient is φ = 5999339520.

The previous prime is 21348387629. The next prime is 21348387659. The reversal of 21348387648 is 84678384312.

21348387648 is a `hidden beast` number, since 21 + 3 + 483 + 87 + 64 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (224).

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

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

It is a junction number, because it is equal to n+sod(n) for n = 21348387594 and 21348387603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 723390 + ... + 752322.

Almost surely, 2^21348387648 is an apocalyptic number.

21348387648 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 21348387648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36452210560).

21348387648 is an abundant number, since it is smaller than the sum of its proper divisors (51556033472).

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

21348387648 is a wasteful number, since it uses less digits than its factorization.

21348387648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29022 (or 29006 counting only the distinct ones).

The product of its digits is 6193152, while the sum is 54.

The spelling of 21348387648 in words is "twenty-one billion, three hundred forty-eight million, three hundred eighty-seven thousand, six hundred forty-eight".