21550001054020 has 12 divisors (see below), whose sum is σ = 45255002213484. Its totient is φ = 8620000421600.

The previous prime is 21550001054011. The next prime is 21550001054083. The reversal of 21550001054020 is 2045010005512.

It can be written as a sum of positive squares in 2 ways, for example, as 2913719269444 + 18636281784576 = 1706962^2 + 4316976^2 .

It is a super-2 number, since 2×21550001054020² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 538750026331 + ... + 538750026370.

It is an arithmetic number, because the mean of its divisors is an integer number (3771250184457).

Almost surely, 2^{21550001054020} is an apocalyptic number.

21550001054020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21550001054020 is an abundant number, since it is smaller than the sum of its proper divisors (23705001159464).

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

21550001054020 is a wasteful number, since it uses less digits than its factorization.

21550001054020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1077500052710 (or 1077500052708 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

Adding to 21550001054020 its reverse (2045010005512), we get a palindrome (23595011059532).

The spelling of 21550001054020 in words is "twenty-one trillion, five hundred fifty billion, one million, fifty-four thousand, twenty".