21771979807104 has 192 divisors, whose sum is σ = 62745725952000. Its totient is φ = 7246379252736.

The previous prime is 21771979807103. The next prime is 21771979807141. The reversal of 21771979807104 is 40170897917712.

It is a tau number, because it is divible by the number of its divisors (192).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21771979807103) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 2385442989 + ... + 2385452115.

It is an arithmetic number, because the mean of its divisors is an integer number (326800656000).

Almost surely, 2^{21771979807104} is an apocalyptic number.

21771979807104 is a gapful number since it is divisible by the number (24) 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 21771979807104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31372862976000).

21771979807104 is an abundant number, since it is smaller than the sum of its proper divisors (40973746144896).

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

21771979807104 is a wasteful number, since it uses less digits than its factorization.

21771979807104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12045 (or 12030 counting only the distinct ones).

The product of its (nonzero) digits is 12446784, while the sum is 63.

The spelling of 21771979807104 in words is "twenty-one trillion, seven hundred seventy-one billion, nine hundred seventy-nine million, eight hundred seven thousand, one hundred four".