21214981440 has 336 divisors, whose sum is σ = 75674866176. Its totient is φ = 5449420800.

The previous prime is 21214981399. The next prime is 21214981481. The reversal of 21214981440 is 4418941212.

21214981440 is a `hidden beast` number, since 2 + 1 + 21 + 498 + 144 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21214981399) and next prime (21214981481).

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

It is a junction number, because it is equal to n+sod(n) for n = 21214981395 and 21214981404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 26158635 + ... + 26159445.

It is an arithmetic number, because the mean of its divisors is an integer number (225222816).

Almost surely, 2^21214981440 is an apocalyptic number.

21214981440 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 21214981440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37837433088).

21214981440 is an abundant number, since it is smaller than the sum of its proper divisors (54459884736).

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

21214981440 is a wasteful number, since it uses less digits than its factorization.

21214981440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1158 (or 1145 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The spelling of 21214981440 in words is "twenty-one billion, two hundred fourteen million, nine hundred eighty-one thousand, four hundred forty".