21553744404 has 12 divisors (see below), whose sum is σ = 50292070304. Its totient is φ = 7184581464.

The previous prime is 21553744393. The next prime is 21553744417. The reversal of 21553744404 is 40444735512.

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

It is a super-2 number, since 2×21553744404² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 898072672 + ... + 898072695.

Almost surely, 2^21553744404 is an apocalyptic number.

It is an amenable number.

21553744404 is an abundant number, since it is smaller than the sum of its proper divisors (28738325900).

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

21553744404 is a wasteful number, since it uses less digits than its factorization.

21553744404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1796145374 (or 1796145372 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 39.

The spelling of 21553744404 in words is "twenty-one billion, five hundred fifty-three million, seven hundred forty-four thousand, four hundred four".