21455416440 has 384 divisors, whose sum is σ = 77710389120. Its totient is φ = 5109350400.

The previous prime is 21455416397. The next prime is 21455416469. The reversal of 21455416440 is 4461455412.

21455416440 is a `hidden beast` number, since 2 + 1 + 4 + 5 + 5 + 4 + 1 + 644 + 0 = 666.

It is a super-2 number, since 2×21455416440² (a number of 21 digits) contains 22 as substring.

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 = 21455416395 and 21455416404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 9282885 + ... + 9285195.

It is an arithmetic number, because the mean of its divisors is an integer number (202370805).

Almost surely, 2^21455416440 is an apocalyptic number.

21455416440 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 21455416440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38855194560).

21455416440 is an abundant number, since it is smaller than the sum of its proper divisors (56254972680).

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

21455416440 is a wasteful number, since it uses less digits than its factorization.

21455416440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2423 (or 2416 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The spelling of 21455416440 in words is "twenty-one billion, four hundred fifty-five million, four hundred sixteen thousand, four hundred forty".