21140893440 has 432 divisors, whose sum is σ = 77441861952. Its totient is φ = 5313724416.

The previous prime is 21140893429. The next prime is 21140893447. The reversal of 21140893440 is 4439804112.

It is a happy number.

21140893440 is a `hidden beast` number, since 211 + 408 + 9 + 34 + 4 + 0 = 666.

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 = 21140893395 and 21140893404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140893447) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 19341534 + ... + 19342626.

Almost surely, 2^21140893440 is an apocalyptic number.

21140893440 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 21140893440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38720930976).

21140893440 is an abundant number, since it is smaller than the sum of its proper divisors (56300968512).

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

21140893440 is a wasteful number, since it uses less digits than its factorization.

21140893440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1216 (or 1199 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The spelling of 21140893440 in words is "twenty-one billion, one hundred forty million, eight hundred ninety-three thousand, four hundred forty".