21820239211680 has 4800 divisors, whose sum is σ = 108475109487360. Its totient is φ = 4080382967808.

The previous prime is 21820239211679. The next prime is 21820239211739. The reversal of 21820239211680 is 8611293202812.

21820239211680 is a `hidden beast` number, since 2 + 182 + 0 + 2 + 392 + 1 + 1 + 6 + 80 = 666.

It is a super-2 number, since 2×21820239211680² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 799 ways as a sum of consecutive naturals, for example, 130660114957 + ... + 130660115123.

Almost surely, 2^{21820239211680} is an apocalyptic number.

21820239211680 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 21820239211680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54237554743680).

21820239211680 is an abundant number, since it is smaller than the sum of its proper divisors (86654870275680).

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

21820239211680 is a wasteful number, since it uses less digits than its factorization.

21820239211680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271 (or 233 counting only the distinct ones).

The product of its (nonzero) digits is 165888, while the sum is 45.

The spelling of 21820239211680 in words is "twenty-one trillion, eight hundred twenty billion, two hundred thirty-nine million, two hundred eleven thousand, six hundred eighty".