21905805557260 has 24 divisors (see below), whose sum is σ = 46584497897280. Its totient is φ = 8651406751104.

The previous prime is 21905805557203. The next prime is 21905805557269. The reversal of 21905805557260 is 6275550850912.

It is a super-2 number, since 2×21905805557260² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21905805557269) 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 7 ways as a sum of consecutive naturals, for example, 6932215369 + ... + 6932218528.

It is an arithmetic number, because the mean of its divisors is an integer number (1941020745720).

Almost surely, 2^{21905805557260} is an apocalyptic number.

21905805557260 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21905805557260 is an abundant number, since it is smaller than the sum of its proper divisors (24678692340020).

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

21905805557260 is a wasteful number, since it uses less digits than its factorization.

21905805557260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13864433985 (or 13864433983 counting only the distinct ones).

The product of its (nonzero) digits is 7560000, while the sum is 55.

The spelling of 21905805557260 in words is "twenty-one trillion, nine hundred five billion, eight hundred five million, five hundred fifty-seven thousand, two hundred sixty".