21436012440 has 192 divisors, whose sum is σ = 71109511200. Its totient is φ = 5598720000.

The previous prime is 21436012421. The next prime is 21436012469. The reversal of 21436012440 is 4421063412.

It is a happy number.

21436012440 is a `hidden beast` number, since 2 + 14 + 3 + 601 + 2 + 4 + 40 = 666.

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, 5510016 + ... + 5513904.

Almost surely, 2^21436012440 is an apocalyptic number.

21436012440 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 21436012440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35554755600).

21436012440 is an abundant number, since it is smaller than the sum of its proper divisors (49673498760).

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

21436012440 is a wasteful number, since it uses less digits than its factorization.

21436012440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4218 (or 4211 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

Adding to 21436012440 its reverse (4421063412), we get a palindrome (25857075852).

The spelling of 21436012440 in words is "twenty-one billion, four hundred thirty-six million, twelve thousand, four hundred forty".