21534554004 has 12 divisors (see below), whose sum is σ = 50247292704. Its totient is φ = 7178184664.

The previous prime is 21534554003. The next prime is 21534554017. The reversal of 21534554004 is 40045543512.

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 (21534554003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 897273072 + ... + 897273095.

It is an arithmetic number, because the mean of its divisors is an integer number (4187274392).

Almost surely, 2^21534554004 is an apocalyptic number.

It is an amenable number.

21534554004 is an abundant number, since it is smaller than the sum of its proper divisors (28712738700).

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

21534554004 is a wasteful number, since it uses less digits than its factorization.

21534554004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1794546174 (or 1794546172 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 33.

The spelling of 21534554004 in words is "twenty-one billion, five hundred thirty-four million, five hundred fifty-four thousand, four".