21663412012440 has 192 divisors, whose sum is σ = 77098686762240. Its totient is φ = 5231767415040.

The previous prime is 21663412012427. The next prime is 21663412012477. The reversal of 21663412012440 is 4421021436612.

21663412012440 is a `hidden beast` number, since 2 + 1 + 6 + 6 + 3 + 4 + 1 + 201 + 2 + 440 = 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 = 21663412012395 and 21663412012404.

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, 9358822 + ... + 11441781.

It is an arithmetic number, because the mean of its divisors is an integer number (401555660220).

Almost surely, 2^{21663412012440} is an apocalyptic number.

21663412012440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21663412012440 is an abundant number, since it is smaller than the sum of its proper divisors (55435274749800).

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

21663412012440 is a wasteful number, since it uses less digits than its factorization.

21663412012440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20800894 (or 20800887 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The spelling of 21663412012440 in words is "twenty-one trillion, six hundred sixty-three billion, four hundred twelve million, twelve thousand, four hundred forty".