21055402368 has 1152 divisors, whose sum is σ = 88483449600. Its totient is φ = 4628275200.

The previous prime is 21055402367. The next prime is 21055402369. The reversal of 21055402368 is 86320455012.

21055402368 is a `hidden beast` number, since 2 + 105 + 540 + 2 + 3 + 6 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (21055402367) and next prime (21055402369).

It is a tau number, because it is divible by the number of its divisors (1152).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21055402363) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 679206513 + ... + 679206543.

It is an arithmetic number, because the mean of its divisors is an integer number (76808550).

Almost surely, 2^21055402368 is an apocalyptic number.

21055402368 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 21055402368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44241724800).

21055402368 is an abundant number, since it is smaller than the sum of its proper divisors (67428047232).

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

21055402368 is a wasteful number, since it uses less digits than its factorization.

21055402368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132 (or 86 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 21055402368 in words is "twenty-one billion, fifty-five million, four hundred two thousand, three hundred sixty-eight".