21400054720 has 112 divisors (see below), whose sum is σ = 55733813856. Its totient is φ = 7761920000.

The previous prime is 21400054679. The next prime is 21400054747. The reversal of 21400054720 is 2745000412.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1403940 + ... + 1419100.

It is an arithmetic number, because the mean of its divisors is an integer number (497623338).

Almost surely, 2^21400054720 is an apocalyptic number.

21400054720 is a gapful number since it is divisible by the number (20) 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 21400054720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27866906928).

21400054720 is an abundant number, since it is smaller than the sum of its proper divisors (34333759136).

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

21400054720 is a wasteful number, since it uses less digits than its factorization.

21400054720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15590 (or 15580 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 25.

The spelling of 21400054720 in words is "twenty-one billion, four hundred million, fifty-four thousand, seven hundred twenty".