21623817239640 has 384 divisors, whose sum is σ = 87985216051200. Its totient is φ = 4474459100160.

The previous prime is 21623817239533. The next prime is 21623817239641. The reversal of 21623817239640 is 4693271832612.

21623817239640 is a `hidden beast` number, since 2 + 1 + 6 + 238 + 17 + 2 + 396 + 4 + 0 = 666.

It is a super-3 number, since 3×21623817239640³ (a number of 41 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623817239641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4993114 + ... + 8257046.

It is an arithmetic number, because the mean of its divisors is an integer number (229128166800).

Almost surely, 2^{21623817239640} is an apocalyptic number.

21623817239640 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 21623817239640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43992608025600).

21623817239640 is an abundant number, since it is smaller than the sum of its proper divisors (66361398811560).

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

21623817239640 is a wasteful number, since it uses less digits than its factorization.

21623817239640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3264207 (or 3264200 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 54.

The spelling of 21623817239640 in words is "twenty-one trillion, six hundred twenty-three billion, eight hundred seventeen million, two hundred thirty-nine thousand, six hundred forty".