21865649493240 has 2304 divisors, whose sum is σ = 92356153344000. Its totient is φ = 4628618588160.

The previous prime is 21865649493221. The next prime is 21865649493251. The reversal of 21865649493240 is 4239494656812.

21865649493240 is a `hidden beast` number, since 2 + 1 + 8 + 6 + 56 + 494 + 93 + 2 + 4 + 0 = 666.

It is a super-2 number, since 2×21865649493240² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 575 ways as a sum of consecutive naturals, for example, 95483185446 + ... + 95483185674.

It is an arithmetic number, because the mean of its divisors is an integer number (40085136000).

Almost surely, 2^{21865649493240} is an apocalyptic number.

21865649493240 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 21865649493240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46178076672000).

21865649493240 is an abundant number, since it is smaller than the sum of its proper divisors (70490503850760).

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

21865649493240 is a wasteful number, since it uses less digits than its factorization.

21865649493240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552 (or 529 counting only the distinct ones).

The product of its (nonzero) digits is 89579520, while the sum is 63.

The spelling of 21865649493240 in words is "twenty-one trillion, eight hundred sixty-five billion, six hundred forty-nine million, four hundred ninety-three thousand, two hundred forty".