21554423121012 has 12 divisors (see below), whose sum is σ = 50293653949056. Its totient is φ = 7184807707000.

The previous prime is 21554423120959. The next prime is 21554423121013. The reversal of 21554423121012 is 21012132445512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554423121013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 898100963364 + ... + 898100963387.

It is an arithmetic number, because the mean of its divisors is an integer number (4191137829088).

Almost surely, 2^{21554423121012} is an apocalyptic number.

It is an amenable number.

21554423121012 is an abundant number, since it is smaller than the sum of its proper divisors (28739230828044).

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

21554423121012 is a wasteful number, since it uses less digits than its factorization.

21554423121012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1796201926758 (or 1796201926756 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 33.

Adding to 21554423121012 its reverse (21012132445512), we get a palindrome (42566555566524).

The spelling of 21554423121012 in words is "twenty-one trillion, five hundred fifty-four billion, four hundred twenty-three million, one hundred twenty-one thousand, twelve".